everything notes

8/2/2019 Everything Notes

1/30

Exam NotesUnit 1: Optics

10.1 Refraction of Light:

Incandescence: Light emitted from a material because of the hightemperature of the material.

Fluorescence: Light that is emitted during exposure of the source toultraviolet light.

Luminescence: The emission of light by a material or an object thathas not been heated; for example, fluorescence.

Phosphorescence: Light that is emitted due to exposure of thesource to ultraviolet light, and continues to be emitted for some timein the absence of the ultraviolet light.

Chemiluminescence: Light that is produced by a chemical reactionwithout a rise in temperature.

Bioluminescence: Light that is produced by a biochemical reactionin a living organism.

Wavelength: The distance from one crest (or trough) of a wave tothe next crest (or trough)

Incandescence is light that is emitted from an object because theobject is very hot.

Luminescence is light that is emitted in the absence of heat.Fluorescence, phosphorescence, chemiluminescence, andbioluminescenceare all forms of luminescence.

Light is transmitted in the form of electromagnetic waves. Visible

light makes up only a small part of the electromagnetic spectrum. Light is used in many technologies. For example, blue, with a special

filter, is used to detect oral cancer.

10.2 Properties of Light and Reflection

Reflection: The change in direction of a light ray when it bounces offa surface.

Medium: The substance through which light travels.

Ray: A straight line with an arrowhead that shows the direction inwhich light waves are travelling.

Incident ray: A ray of light that travels from a light source toward a

surface. Angle of incidence: The angle between the incident ray and the

normal in a ray diagram.

Normal: A line that is perpendicular to a surface where a ray of lightmeets the surface.

Reflected ray: A ray that begins at the point where the incident rayand the normal meet.


2/30

Angle of reflection: The angle between the reflected ray and thenormal in a ray diagram.

Plane Mirror: A mirror with a flat, reflective surface.

Virtual image: An image formed by rays that appear to be comingfrom a certain position, but are not actually coming from this

position; image does not form a visible projection on the screen. A ray is a straight line with an arrowhead that shows the direction in

which light is travelling.

The laws of reflection state that the angle of reflection is equal to theangle of incidence, and that the reflected ray always lies on the planethat is defined by the incident ray and the normal.

The location of an image in a plane mirror can be found by drawing aray diagram based on the laws of reflection and tested throughinquiry.

The four characteristics of an image in a plane mirror are thefollowing: the image is the same size as the object, the samedistance from the mirror as the object, and the same orientation asthe object; the image is a virtual image.

10.3 Images in Concave Mirrors

Concave mirror: A mirror whose reflecting surface curves inward.

Principal axis: On a concave, the line that passes through thecentre of curvature, C, of the mirror and is normal to the centre of themirror.

Focal point: The point on the principal axis through which reflectedray passes when the incident rays are parallel to and near the

principal axis. Focal length: The distance between the vertex of a mirror and the

focal point.

Real image: An image that is formed when reflected rays meet.

Magnification: The change in size of an optically produced image.

Spherical aberration: Irregularities in an image in a curved mirrorthat result when reflected rays from the outer parts of the mirror donot go through the focal point.

The reflected surface of a concave mirror curves inward.

Rays that travel toward a concave mirror, parallel to and near theprincipal axis, will reflect and pass through the principal axis at thefocal point, F.

For an object between the focal point and the concave mirror, thevirtual, upright image is larger than the object, and the imagedistance is larger than the object distance.

For an object between the focal point and the centre of curvature, thereal, inverted image is larger than the object, and the image distanceis larger than the object distance


3/30

For an object beyond C, the real, inverted image is smaller than theobject, and the image distance is smaller than the object distance.

You can calculate the image distance and size using the mirrorequation 1/F= 1/Di + 1/Do, and the magnification equation, m=Hi/Ho= -Di/Do.

Spherical aberration is the distortion of an image in a curved mirrorthat results when reflected rays from the outer parts of the mirror donot go through the focal point.

10.4 Images in Convex Mirrors

Convex Mirror: A mirror whose reflecting surface curves outward.

The reflecting surface of a convex mirror is a mirror that curvesoutward.

Rays that travel toward a convex mirror, parallel to and near theprincipal axis, will reflect back and spread out, away from each other.

To find F for a convex mirror, extend the reflected rays backwardsuntil they appear to meet behind the mirror.

For an object in a convex mirror, the virtual, upright image is smallerthan the object.

You can predict the location and size of an image in a convex mirrorby drawing the bottom of the object on the principal axis and drawingat least two rays that travel from the top of the object toward themirror.

You can calculate the image distance and size using the mirrorequation 1/F= 1/Di + 1/Do, and the magnification equation, m=Hi/Ho= -Di/Do.

The focal length of a convex mirror is negative because the F isvirtual and behind the mirror.

There are many practical uses for convex mirrors and surfaces, suchas security mirrors and inspection mirrors.

11.1 Refraction of light

Refraction: The bending of light that travels, at an angle, from amaterial with one refractive index to a material with a differentrefractive index.

Refracted ray:The ray that is bent upon entering a second medium.

Angle of refraction:The angle between the normal and a refracted

ray. Index of refraction:The ratio of the speed of light in a vacuum to

the speed of light in a given medium.

Dispersion:The process of separating colours by refraction.

Light rays refract when they cross a boundary between media inwhich the speeds of light are different.


4/30

If a light ray goes from a medium in which its speed is higher (such asair) into a medium in which the speed is lower (such as water), therefracted ray bends toward the normal

If a light ray goes from a medium in which its speed is lower (such aswater) into a medium in which the speed is higher (such as air), the

refracted ray bends away from the normal

11.2 Partial Refraction and Total Internal Reflection

Partial Reflection and Refraction: A phenomenon in which someof the light that is travelling from one medium into another isreflected and some is refracted at the boundary between the media.

Critical angle: The angle of incidence that produces an angle ofrefraction of 90.

Total Internal Reflection: The phenomenon in which incidencelight is not refracted but is entirely reflected back from the boundary;occurs when light travels from a medium in which its speed is lower

to a medium in which its speed is higher. When light strikes a boundary between two transparent media that

have different indices of refraction, some light reflects off theboundary and some light refracts through the boundary. Thisphenomenon is called partial reflection and refraction.

At a small angle of incidence, more light refracts than reflects. As theangle of incidence increases, more and more light reflects thanrefracts.

When light travels from a medium with a lower index of refraction toa medium with a higher index of refraction, the angle of refraction is

larger than the angle of incidence. Therefore, an angle of incidencethat results in a 90angle of refraction is eventually reached. Theangle of incidence is called the critical angle.

When the angle of incidence is larger than the critical angle, norefraction occurs. All the light is reflected from the boundary. Thisphenomenon is called total internal reflection.

Total internal reflection has many practical applications, such asbinoculars, retro reflectors, and optical fibres in telecommunicationsand in surgical instruments.

11.3 Optical Phenomena in Nature

Rainbow: An arc of colours of the visible spectrum appearingopposite the Sun, caused by reflection, refraction, and dispersion ofthe Suns rays as they pass through raindrops.

Apparent depth: An optical effect in which the image of an objectappears closer than the object.

Shimmering: The apparent movement of object in hot air overobjects and surfaces.


5/30

Mirage: An optical effected caused by the bending of light passingthrough layers of air that have extremely different temperatures.

A rainbow is formed by the refraction and total internal reflection oflight and the resulting dispersion of the light b spherical waterdroplets in the sky.

As a result of the refraction of light at the surface of water, objectsunder the water are not where they appear to be when you arelooking at them from above the water. The level at which they appearto be is called their apparent depth.

Shimmering is the apparent movement of objects seen through airthat is unevenly heated and moving.

A mirage is the appearance of water or another object that is notreally there. A mirage is caused by light being continuously refractedby layers of air that are at extremely different temperatures.

12.1 Characteristics of Lenses

Lens: A transparent object with at least one curved side that causeslight to refract.

Converging lens: A lens that bring parallel light rays toward acommon point.

Diverging lens: A lens that spread parallel light rays away from acommon point.

Chromatic aberration: The dispersion of light through a lens.

Lenses are classified as either converging or diverging, depending onhow they affect parallel light rays that refract through them.

Converging lenses have one or two convex surfaces and are thicker

in the centre than on the edges. Diverging lenses have one or twoconcave surfaces and are thinner in the centre than on the edges.

The focal point of a converging lens in the point at which parallel raysmeet after passing through the lens. The focal point of a diverginglens is the point from which the diverging rays appear to have comeafter parallel rays have pass through the lens.

With thick lenses, rays that are farther from the principal axis do notpass through the focal point. This causes spherical aberration.

Different colours of light have different indices of refraction.Therefore, they focus at different. This causes chromatic aberration.

12.2 Images Ray diagrams consisting of three rays can be drawn of determine the

characteristics of images formed by lenses.

When an object is between a converging lens and the focal point, theimage is always virtual upright, and larger than the object.

When an object is farther from a converging lens than the focal point,the image is always real and inverted.


6/30

When a diverging lens forms an image, it is always upright, virtual,smaller than the object, and on the same side as the object.

Given the focal length of the lens and the size and location of theobject, you can use algebraic equations to calculate thecharacteristics of the image.

12.3 Lens Technologies and the Human Eye

Objective lens: The lens through which light enters a telescope.

Eyepiece: The lens in a telescope through which the observer viewsthe object and through which light leaves the telescope.

Cornea: Tissue that forms a transparent, curved structure in thefront of the eye; refracts light before it enters the eye.

Retina: A layer of rod and cone cells that respond to light and initiatenerve impulses; rod cells are very sensitive to light but cannotdistinguish between colours; cone cells detect colour.

Myopia: Near-sightedness; the condition in which the eye cannotfocus on distant objects.

Hyperopia: Far-sightedness; the condition in which the eye cannotfocus on nearby objects.

Presbyopia:The condition in which lenses of the eye become stiffand the ciliary muscles can no longer make the lenses change shape.

Astigmatism: Blurred or distorted vision usually caused by anincorrectly shaped cornea.

Night-vision device: An artificial device that allows people to seewhen only a very small amount of light is available.

Lenses are used in several technologies. For example, microscopes

are used to magnify specimens. Microscopes are used in many fields. The cornea refracts light first. Then the eye lens focuses light once

the light enters the eye.

Myopia (near-sightedness) is caused by an eyeball that is too long.Hyperopia (far-sightedness) is caused by an eyeball that is too short

Presbyopia prevents a person from being able to focus up close andis caused by the hardening of the eye lens. Astigmatism causesblurry vision because the cornea isnt perfectly round.

Myopia, hyperopia, presbyopia, and astigmatism can be correctedwith eyeglasses contact lenses, and surgery.

People in the military and law enforcement and people studyingwildlife use night-vision devices to intensify the available light.

Unit 2: Chemistry

4.1 Representing Ionic Compounds

Ionic compound: A compound composed of oppositely charged ions


7/30

Ion: A charged particle formed from the loss or gain of one or moreelectrons.

Cation: A positively charged ion.

Anion: A negatively charged ion.

Valence electron: An electron in the outermost occupied energy

level. Binary ionic compound: A compound composed of a metal cation

and a non-metal anion.

Polyatomic ion: An ion that is composed of more than one atom.

Ternary compound: A compound composed of three differentelements.

Ionic compounds are composed of oppositely charged ions, calledcations and anions.

Solid ionic compounds are made up of repeating patterns of ions thatoccur in specific ratios. The chemical formula for an ionic compound

shows the ratio of ions. Subscripts are used in the chemical formula fro an ionic compound to

show the ratio of ions needed to make the charge zero.

The name of an ionic contains the name of cation followed by thename of the anion. For binary ionic compounds, the part thatrepresents the anion always ends with the suffix ide.

When naming compounds with multivalent metals, a Roman numeralis used to indicate the ion form of the metal.

Ternary ionic compounds contain polyatomic ions, which arecomposed of more than one atom. Polyatomic ions have specificnames that are based on the group of atoms present.

4.2 Representing Molecular Compounds

Molecular compound: A compound formed when atoms of two ormore different elements share electrons.

Molecule: A neutral particle composed of two or more atoms joinedtogether by covalent bonds.

Binary molecular compound: A compound that is composed of twonon-metals joined by one or more covalent bonds.

Molecular compounds form when atoms share electrons in covalentbonds.

Prefixes are used in the name of the binary molecular compound toindicate the number of atoms of each element in a molecule of thecompound.

The chemical formula for binary molecular compounds shows thenumber of each atom in a molecule of the compound. The subscriptscorrespond to the prefixes in the name of the compound.

Molecular compounds have important functions in en ergygeneration and in the production of chemicals used by agricultural


8/30

industries. Many molecular compounds, however, are environmentpollutants. Other molecular compounds can have negativeconsequences if they are not handled correctly.

4.3 Conservation of Mass and Chemical Equations

Reactant: A pure substance that undergoes a chemical change.

Product: A pure substance that is formed in a chemical change; theproperties of the products are different from the properties of thereactants.

Chemical reaction: A process in which new substances with newproperties are formed.

Chemical equation: A representation of what happens to thereactants and products during a chemical change.

Coefficient: A number that is placed in front of a chemical formulain a balanced chemical equation.

The law of conservation of mass states that the total mass of thereactants must equal the total mass of the products in a chemicalreaction.

A chemical reaction can be represented by a word equation, in whichthe names of the reactants and products shown, or by a skeletonequation, in which the chemical formulas of the reactants andproducts are shown.

A balanced chemical equation has coefficients in front of thechemical formulas. The number of atoms of each element is the samein the reactants and the products.

An understanding of the law of conservation of mass can be applied

to the clean up of hazardous materials and the manufacture ofproducts, to reduce potential harm or waste.

5.1 Synthesis and Decomposition Reactions

Precipitate: An insoluble solid formed in a chemical reaction.

Synthesis reaction: A chemical reaction in which two or morereactants combine to produce a new product.

Decomposition reaction: A chemical reaction in which a compoundbreaks down (decomposes) into two or more simpler compounds orelements.

Evidence of a chemical change may include one or more of the

following: formation of gas, formation of precipitate, change in odour,change in colour, change in temperature, and production of light.

During a synthesis reaction, two or more reactants combine to formone product. The general chemical equation for a synthesis reactionis A + B -> AB. The reactants may be any combination of elementsand compounds, but the product will always be a compound.

During a decomposition reaction, a single reactant breaks down toform tow or more products. The general chemical equation for a


9/30

decomposition reaction is AB -> A + B. The products may be anycombination of elements and compounds, but the reactant willalways be a compound.

Examples of synthesis reaction include the formation of rust andproduction of ammonia. Important decomposition reactions include

the electrolysis of water and the explosion of TNT.

5.2 Displace Reactions

Single displace reaction: A chemical reaction in which oneelement takes the place of another element in a compound.

Activity series: A list of elements organized according to theirchemical reactivity: the most reactive element appears at the topand the least reactive element appears at the bottom.

Double displacement: A chemical reaction in which the positiveions of tow different compounds exchanges places, resulting in theformation of two new compounds-one of which may be a precipitate.

In a single displacement reaction, a metal replaces the ion of adifferent metal, or a non-metal replaces the ion of a non-metal. Theproducts are an element and a compound that different from thereactants

An activity series is a list of elements arranged in order from themost reactive to the least reactive. For a single displacement tohappen, a more reactive element must replace the ion of a lessreactive element.

During a double displace reaction between two compounds inaqueous solutions, the cations of the two compounds switch places tofrom two new compounds. For a certain type of double displacementreaction, one of the products is a precipitate.

5.3 Reactions and Environmental Issues

Catalyst: A substance that increases the rate of a reaction and isregenerated at the end of the reaction.

Leaching: A technique used to extract a metal by dissolving themetal in an aqueous solution.

Catalytic converters are used to help combat pollutants from carexhaust. They act by decomposing nitrogen oxides in exhaust intothe element nitrogen and oxygen.

The gold mining process relies a great deal on chemistry. Gold formsa soluble substance with cyanide ion. Zinc displaces the gold so thatthe metal can be recovered. The use of cyanide-containingchemicals, however, results in several environment challenges.

Bleach and other chlorine-based chemicals are used to disinfectants.Improper handling and mixing with other chemicals, such asammonia can result in reactions that produce toxic gases.


10/30

Users of a product can find information about how to handle and useit safely by examining the safety precautions and symbols on theproducts label. For laboratory and workplace products, WHMISsymbols are used. For consumer produce, the HHPS system is used.

6.1 Identifying Acids and Bases Acid: A compound that produces hydrogen ions, H+ (aq), when

dissolved in water.

Binary acid: An acid composed of hydrogen and a non-metal.

Oxoacid: An acid composed of hydrogen, oxygen, and anotherelement.

Base: A compound that forms hydroxide ions, OH- (aq), whendissolved in water.

Acids are compounds that have a sour taste. When dissolved inwater, they produce hydrogen ions, H+ (aq).

Binary acids are composed of hydrogen and a non-metal. The nameof a binary acid is written using the prefix hydro-, the root of the non-metal name, and the ending ic acid.

Oxoacids that form between hydrogen and polyatomic ions arenamed by replacing ate with ic acid and ite with -ous acid.

Bases are compounds that have a bitter taste. Many bases are ioniccompounds that separate into metal ions and hydroxide ions, OH-(aq) when dissolved in water.

Since bases are ionic compounds, their names and chemical formulasare written following the same rules that are used for ioniccompounds.

6.2 The pH Scale and Indicators

pH scale: A numerical scale ranging from 0 to 14 that is used toclassify aqueous solution as acidic, basic, or neutral.

pH indicator: A substance that change colour to show theconcentration of hydrogen ion (H+) and hydroxide ions (OH-) in asolution.

The pH scale ranges form 0 to 14 and is used to classify an aqueoussolution as acidic, basic, or neutral. Neutral solutions are pH 7. Acidicsolutions have a pH less than 7. Basic solutions have pH grater than7.

A change of 1 on the pH scale represents a change in theconcentration of hydrogen ions in a solution by a factor of 10. The pHof a solution can be determined using pH indicators or an electronicpH probe.

A pH indicator is a chemical that is added in small amounts to asolution to visually show the acidity or basicity of the solution bycharging colours within a small range of pH values.


11/30

Universal pH indicator and pH paper contain several indicators andcan be used to determine the pH of a solution.

6.3 Reactions of Acids and Bases

Neutralization:The reaction of an acid and a base to produce a salt

and water. Liming: The application of basic material, typically lime-based, to

renew acidified lakes and regions.

A neutralization reaction occurs when an acid and a base react toform water and a salt.

Acid precipitation forms from non-metal oxides such as the oxides ofsulphur and of nitrogen. These oxides in the atmosphere react withthe water to form acids. Scrubbers are used to remove sulphurdioxide form exhaust gases.

Acid precipitation can have detrimental effects, particularly on riverand lakes. Renewing a lake involved adding limestone to the water tohelp neutralize the acid and raise the pH.

The properties of acids make them useful for extracting metals fromores, but the process may contaminate an area. These sameproperties also mean that acids are useful for leaching toxic metalsfrom contaminated soils.

Unit 3: Ecology

1.1 Silence of the Frogs

Ecosystem: In an area defined by an ecologist, the set relationships

between populations of species and between those populations andthe abiotic (non-living) factors in their environment

Food Chain: A step-by-step sequence linking organisms that feed oneach other, starting with a food source, such as a producer ordetritus, and continuing with a sequence of consumers

Producer or Autotroph: An organism that uses photosynthesis oranother form of chemical synthesis to make food

Primary Consumer or Heterotroph: In a food chain or food web, anorganism that relies on autotrophs directly for its source of energy;organisms at the second trophic level

Secondary Consumer or Heterotroph: In a food chain or food web, anorganism that relies on primary consumers for its principal source ofenergy; organisms at the third trophic level

Herbivore: An animal that eats plants

Carnivore: An animal that eats other animals

Omnivore: An animal that eats both plants and animals

Detritus: Waste from plants and animals, including all their deadremains


12/30

Decomposers: An organism that feeds on detritus, in the process ofreleasing nutrients to the soil and water, where they can be used byother organisms

Habitat: The conditions required for the survival of species

The four major cause of the decrease in the frog population are:

1) Loss of Habitat2) Air and Water Quality3) Ultraviolet Radiation4) Climate Change

1.2 Canadas Endangered SpeciesClassification Description

Extinct A species that is no longer foundanywhere

Endangered A species that is close to extinctionin all parts of Canada or in a

significantly large locationExtirpated Any species that no longer exists in

one part of Canada, but can befound in others

Threatened Any species that is likely tobecome endangered if factors that

make it vulnerable are notreversed

Vulnerable Any species that is at risk becauseof low or declining numbers at the

fringe of its range or in somerestricted area

1.3 Extinction in the Modern World

Between 1600 and 1900 the estimate was that species went extinctevery four years

In modern times, the extinction rate is soaring

In early years of the 21st century, the prediction was that one specieswould become extinct every 30 minutes

The number of species at risk of extinction is growing, at the rate ofabout 80 species per year

Mass extinction occurred before humans existed The most promising of theories involve asteroids crashing into the

Earth

A collision would raise tremendous amount of dust, blocking lightfrom the Sun, and set off many volcanoes, quickly alteringenvironmental conditions

There is evidence that an asteroid hit Earth about 65 million yearsago


13/30

It is estimated that nearly 500 million different species had inhabitedthe planet

Of these, more than 90% have either become extinct or have evolvedinto new species

Climate changes and the pressure of competition from other species

force organism to adapt or die A species that is better at finding food, reproduction, or defending its

territory could force competing species into extinction

Biodiversity: The number of species in an ecosystem, and the varietywithin those species

Every organism in an ecosystem is connected to all the otherorganisms, the reduction in biodiversity caused by the extinction of asingle species can cause a domino effect

The removal of one part from an ecosystem, like the removal of amoving part from a car, can cause the collapse of an entire foodchain.

When the threatened species act as a predator, it keeps thepopulation of it prey in check; when it acts as prey, it provides animportant food sources

1.5 Ecology

Pests: An organism that people consider harmful or inconvenient in aparticular situation, such as weeds and some insect, fungi, androdents

Ecology: The study of the interactions of living things with each otherand with abiotic (non-living) factors in their environment

Abiotic Factor: Factor in an ecosystem, created by non-living agents,for example, the amount of sunlight, temperature, and strength anddirection of wind

Biotic Factor: A factor in an ecosystem created by the presence androles of other living things

Community: The collection of all the populations of all the species inan ecosystem; all of the organism in an ecosystem

Population: All the members of a species living in the sameecosystem or habitat

Ecotones: A transition area between two ecosystem that includesmembers of the community of both ecosystem

Ecosystems rarely have sharp boundaries, and organism can moveback and forth from one ecosystem to another

Ecosystems with greater biodiversity tend to be less fragile

In ecotones and other diverse areas there are more species, andpredator may have an alterative if something happens to thepopulation of it main prey


14/30

1.8 Comparing Ecosystems

Artificial Ecosystem: An ecosystem that is planned and maintained byhumans, for example, a park, a farm, or a garden

Natural Ecosystem: An ecosystem that is neither planned normaintained by humans, an ecosystem which organism are free to

interact and change their interaction without human interference Change within a park is limited because of human interference

Natural ecosystems undergo subtle changes as one plant or animalspecies gradually replaces another

In natural ecosystems, only plants suited for the environment flourish

In an artificial ecosystem, plants selected by humans have anadvantage

1.10 Energy in Ecosystems

The source of all energy for ecosystem is the Sun

Sunlight also provides the energy used by green plants to make thecompounds that maintain their lives and serve as food for all otherorganisms

Of the energy that penetrates into the lower atmosphere, 30% isreflected by clouds or the Earths surface

The remaining 70% warms the surface of the planet, causing water toevaporate, and generating the water cycle and weather

Only a tiny portion, approximately 0.023%, is actually used by greenplants for photosynthesis

Photosynthesis: The process by which green plants and some otherorganism use sunlight energy, carbon dioxide, and water to produce

carbohydrates (sugars) and oxygen When sunlight strikes and object, some of the energy is absorbed,

and some is reflected

Albedo: a measurement of the percentage of light that an objectreflects; the higher albedo, the greater the objects ability to reflectthe sunlight

For the Earth, the higher its overall albedo, the less energy will beabsorbed and available for maintaining the global temperature

1.11 Following Energy Movement in Ecosystems

Trophic Level: A way of categorizing living things according to howthey gain their energy; the first trophic level contain autotrophs, andeach higher level contains heterotrophs

Autotroph: An organism that uses energy and raw materials to makeits own food, whether from photosynthesis or some other form ofchemical synthesis; a producer


15/30

Primary Consumer: In a food chain or food web, an organism thatrelies on autotrophs directly for its source of energy; organisms at thesecond trophic level

Secondary Consumer: In a food chain or food web, an organism thatrelies on primary consumers for its principal source of energy;

organisms at the third trophic level Heterotroph: An organism that is incapable of making its own food,

and so must feed on other organisms to gain energy

Every organism within an ecosystem provides energy for otherorganisms

Food chains are a way of showing a step-by-step sequence of whoeats whom in an ecosystem

The final carnivore in any food chain is called the top consumer

Food Chain: A step-by-step sequence linking organisms that feed oneach other, starting with a food sources, such as a producer ordetritus, and continuing with a sequence of consumers

The lower the biodiversity of an ecosystem, the simpler the food web,and the more vulnerable each organism is

Producers use energy from sunlight and basic nutrients to makemolecules of sugar

Sugar molecules contain the chemical energy that drive ecosystems

Photosynthesis provides the energy required by the entire ecosystem

Without photosynthesis, energy would not move from the abioticenvironment to living things

Solar energy must be converted chemical energy before it can beused by living things

Thermodynamics is the study of energy transformations The first law of thermodynamics states that although energy can be

transformed (changed) from one form to another, it cannot becreated or destroyed

Biomass: A pyramid-shaped measure of the mass of the dry mattercontained in a group of living things, whether of a specie, a class ofspecie, or all of the organism within an ecosystem

1.12 Roles in Ecosystem

Each organism has it own place within an ecosystem

The organisms place in the food web, it habitat, breeding area, andthe time of day that it most active is its ecological niche.

Ecological Niche: The place or role of a species within an ecosystem;everything an organism does to survive and reproduce, including itsplace in the food web, its habitat, its breeding area, and the time ofday that it is most active

Exotic Species: The introduction of a new specie in an ecosystem


16/30

The niche an organism fills in an ecosystem includes everything itdoes to survive and reproduce

Each species in an ecosystem tends to have a different niche, adifferent role to play

The introduction of new species (often called exotic species

because they are not native to the ecosystem) happens naturally This helps reduce competition between species for the same territory

and resources

Do Practice Questions Nao!

2.1 Cycling of Matter in Ecosystems

All organic matter is recycled in the world

Organic substance always contain atoms of carbon and hydrogen,and often contain oxygen and nitrogen atoms

Organic: Compounds that contain atoms of both carbon andhydrogen; many organic compounds also contain oxygen andnitrogen atoms; sugars, fats, and proteins are all organic

Matter that doesnt contain a combination of carbon and hydrogenatoms are called inorganic

Inorganic: Compounds that do not contain a combination of carbonand hydrogen atoms; carbon dioxide, water, and ammonia are allinorganic

Another process involved in the cycling of mater is decay

Organic matter is held temporary in the bodies of living organisms

After death, decomposer organism make the material available to

other living things Decomposer break down the organic matter in dead bodies and feces

into small, inorganic molecules

These small particles pass into the soil or water, where they becomepart of the living world at some time in the future.

2.2 Case Study

Pesticides are chemical designed to kill pests

Pests: An organism that people consider harmful or inconvenient in aparticular situation, such as weeds and some insect, fungi, and

rodents Pesticides: A chemical designed to kill pests; pesticides are often

used to protect species that are beneficial to humans from acompetitor or predator that is less useful

First-generation pesticides had used dangerous metals and toxins tokill these pests

Second-generation pesticides are chemical made in laboratories


17/30

Bioamplification: Even though there is a small amount of toxinreaching each of the prey animals that a secondary consumer eatsthe amount of toxin in its body will be larger because each predatoreats many preys.

When the secondary consumer is eaten, the higher-level predator

gets all of its toxins, plus those of all the other prey it eats At each stage of the food chain the concentration becomes greater

The higher the trophic level, the greater the concentration of toxins

Even though insecticides were meant for insect due tobioamplification, there toxins are also found in humans

Chemicals pesticides have a natural shelf life, because pest they aresupposed to kill gradually become resistant.

If the first application of a chemical kills 90% of the insects, that stillleave 10% that survive

Some of those insects have genes that help them survive theapplication of the pesticide

With every generation that pass, they eventually build a resistance tothe pesticide

2.4 The Interaction of Living Things

Photosynthesis: the process by which green plants and some otherorganism use sunlight energy, carbon dioxide, and water to producecarbohydrates (sugars) and oxygen

Carbon Dioxide + Water sugar + oxygen

Cellular Respiration: The process by which most living generateuseful energy, combining sugars and oxygen to produce carbon

dioxide and water Sugar + Oxygen Carbon Dioxide + Water

Within a biosphere a balance of oxygen and carbon dioxide ismaintained because the plants provide oxygen and sugars, whileanimals provide carbon dioxide and water

The processes of photosynthesis and cellular respiration are said tobe complementary

2.5 The Carbon Cycle

Carbon is key to all living things

Carbon can be found in the atmosphere and dissolved in the oceansas part of the inorganic carbon dioxide

This is done through photosynthesis

The burning process (combustion) releases carbon dioxide into theatmosphere

When carbon is not in organic form, carbon can be found in threemain reservoirs (storage areas): the atmosphere, the oceans, and theEarths crust


18/30

Organic carbon is also held in reservoirs the bodies of living things

Carbon atoms may remain locked away in dead plant matter (peat)for many years in a bog

Humans have modified the global carbon cycle by releasing carbonfrom organic reservoirs faster than that it would normally occur; by

mining and burning fossil fuels trapped in Earths crust, and byburning forest

Humans are also increasing the amount of carbon dioxide in theinorganic reservoir of the atmosphere by clearing away vegetation, inorder to build or farm

2.6 Nitrogen Cycle

Nitrogen atoms are required so that cells can make proteins

The movement of nitrogen through ecosystems, the soil, theatmosphere is called the nitrogen cycle

Nitrogen Cycle: A matter cycle in which, the through the processes ofnitrogen fixation, synthesis, decomposition, and denitrification,nitrogen atoms move from nitrogen gas in the atmosphere, toinorganic form in the soil, to organic form in living, and then back toinorganic form in the soil and nitrogen gas in the atmosphere;organic compounds that contain nitrogen include amino acids (andtherefore proteins) and DNA

Nitrogen gas composes nearly 79% of the Earths atmosphere

Atmospheric nitrogen can be converted into nitrates, in a processcalled nitrogen fixation

The first method is through lightning, and the second is through

bacteria in the soil Nitrogen Fixation: Eventually, the nitrogen gas is released back into

the atmosphere, this process is called denitrification, which is carriedout by bacteria that do not require oxygen

Denitrification: Denitrification ensures the balance and soil nitrates,nitrites, and atmospheric nitrogen and completes the nitrogen cycle

Phosphorus tends to cycle in two ways: a long-term cycle involvingthe rocks of the Earths crust, and a short-term cycling involvingliving organism

In the short cycle, wastes from living things are recycled bydecomposers, which break down waster and dead tissue and release

the phosphates The short cycle is much more rapid

Nitrates and phosphates are both nutrients

Nutrients: Any chemical that is essential to living things; nutrients arecycled through ecosystems and geological processes

2.9 Monitoring Changes in Population


19/30

Natality: The number of offspring of a species born in an ecosystemin one year

Morality: The number of individuals of a species that die in anecosystem in one year

Open population: A population in which natality, mortality,

immigration, and emigration are all acting Closed population: A population in which only natality and mortality

(not emigration and immigration) are acting

2.10 Limits on Populations

Biotic potential is the maximum number of offspring that specie couldproduce, if resources were unlimited

Biotic Potential: The maximum number f offspring that a speciescould produce, if resources were unlimited

Four important factors that regulate biotic potential are:1) Birth potential (maximum number of births)2) Capacity for Survival (The number of offspring that reachreproductive age) 3) Procreation (The number of timesthat a species reproduces each year) 4) Length ofReproductive Life (the age of sexual maturity)

Factors that Limit Populations:

Biotic: Sufficient food, low number or low effectiveness of predators,few or weak diseases and parasites, and ability to compete forresources

Abiotic: Favourable light, favourable temperature, and favourablechemical environment

Carrying Capacity: The maximum population of a species that can besupported indefinitely by an ecosystems

Law of the Minimum: The nutrient in least supply is the one that limitsgrowth

Law of Tolerance: States that an organism can survive within(tolerate) a certain range of an abiotic factor above and below thislimit can not survive; the greater this range of tolerance, the greaterthe organisms ability to survive

Density-Independent Factors: A factor that affect population in amanner that does not vary according to the density of the populationit is acting on, for example, fire and flood

Density-Dependent Factors: A factor in an ecosystem that affects apopulation, and that increases or decreases its effect based on thedensity of the population, for example, food supply, territory, andsome forms of diseases



20/30

3.1 Canadian Biomes

The tundra is like a cold desert and receives surprisingly littleprecipitation often only 10 to 12 cm

Tundra: The huge treeless region, between the northern limits ofCanadas tree line and the permanently ice-covered area in the

arctic; it is dominated by lichens and small plant such as moss,sedge, and short grasses; its biodiversity and average precipitationand temperature are is low, and its soil is thin and low in fertility

Permafrost: In the tundra, a layer of soil that remains frozen, even insummer

Active Layer: In the tundra, a layer of soil above the permafrost thatthaws in summer; this soil permits the uptake of water and mineralsby plant roots

Immediately south of the tundra is the boreal forest, or taiga, biome

Dominated by conifers (tree with needle-shaped leaves), the borealforest is found in every province and makes up 80% of the forestedareas

Boreal Forest: A biome dominated by coniferous trees; the mostextensive biome in Canada; its biodiversity can be high or moderate,precipitation may be moderate or high, temperatures vary, and soil isoften thing an slightly acidic

South of the boreal forest, in Eastern and Central Canada, is thetemperate deciduous forest biome, which is dominated by deciduoustrees such as maples and oaks

The transition from boreal forest to deciduous forest produces a wideecotone where trees native to both biomes can be found

Temperate Deciduous Forest: A biome dominated by deciduous trees birch and maple in the north, oak and beech in south; this biome islimited to the area south this biome is limited to the area south of theboreal forest in Eastern and Central Canada; its biodiversity is high,precipitation is moderate, temperature are moderate, temperaturesare moderate, and soil is mostly thick and fertile

Grassland biome is found at approximately the same latitude asdeciduous forest.

Grassland: A biome dominate by grasses, it is found in Canada atapproximately the same latitude as deciduous forest, but in areaswhere average precipitation is lower; its biodiversity is moderate,

precipitation is low to moderate, temperatures are moderate, and soilis thick and very fertile

3.3 Soil and Its Formation

Soil can be viewed in series of layers

In a forest or grassland community, the upper layer, known as thelitter, is made up mostly of partially decomposed leaves or grasses


21/30

Litter: The upper of layer of soil, made up mostly of partiallydecomposed leaves or grasses

Beneath the littler is the topsoil layer, made up of small particle ofrock mixed with decaying plant and animal matter (humus)

Topsoil: A layer of soil, below the litter, made up of small particles of

rock, usually mixed with relatively large amount of decaying plantand animal matter

Humus: The organic component of soil, made up of mostly ofdecomposing plants

Below the topsoil is the subsoil, a layer tat usually contains morestones, mixed with only small amount of organic matter

Subsoil: A layer of soil, below the topsoil, that usually contains manystones and only small amounts of organic matter

Beneath the soil lies a layer of rock, the bedrock, which marks theend of the soil

Precipitations that collects and flows above the ground is calledsurface water

Surface Water: Water in lakes, ponds, rivers, and streams

Once in the soil or rock water is called ground water

Ground Water: The water found in the soil or rock layers of theEarths curst; may flow out on to the surface (as it does at springs) orinto bodies of surface water

Percolation: The process in which ground water, pulled by gravity,flows downward through the soil

Water Table: The boundary, found either in the soil or in bedrock,between the area where ground water is percolation down and a

layer tat is saturated with water Leaching: A process in which nutrients such as organic matter and

minerals are dissolved in percolating water and carried into lowerlayers of soil or bedrock

Acid Deposition: A term used to describe the falling of acids from theatmosphere to the ground, where dissolved in precipitation or assolids

3.11 Acid Deposition and Forest Ecosystems

Coal-burning plants, cars and trucks, metal smelters, and oil

refineries provide energy, transport, and material for the industrialword, but at the same time produce oxides of sulfur and nitrogen, areamong the most dangerous of air pollutants.

When sulfur and nitrogen enter the atmosphere they mancombine with water droplets to form acids.

Upon entering the water cycle, the acids return to the surface ofthe Earth in the form of snow or rain, called acid precipitation.


22/30

Acid precipitation: a form of acid deposition in which acids aredissolved in rain, fog, dew, or snow; this precipitation has a pH of lessthan 5.6 (the pH of normal rainwater)

Acid rain is 40 times more acidic than normal rainwater that hasbeen measured.

Acid precipitation kills fish, soil, bacteria, and both aquatic andterrestrial plants.

Acid rain has medical effects, which include acceleratedrespiratory problems, such as asthma and bronchitis.

As acid rain falls to the soil, it kills bacteria that are important tothe nitrogen cycle.

The biggest acid rain threat is the automobile.

The problems worsened by the spread of automobile use.

As developing countries makes economic gains, the demand forcars within those countries increases.

The issue is the there is a new source of pollutant for an alreadyoverloaded atmosphere.


4.1 Abiotic Factors in Lakes

The littoral zone is the area extending out from the lakeshore to thepoint where plants rooted in the bottom of the lake can no longer befound

Littoral Zone: The area extending out from out from the lakeshore tothe point where plants rooted in the bottom of the lake can no longer

be found Beyond the littoral zone is the limnetic zone, the area of the open

lake where there is enough light for photosynthesis

Limnetic Zone: The area of the open lake, beyond the littoral zone,where there is enough light for free-floating organism, such as algae,to carry out photosynthesis

The most common form of organism within the limnetic zone is calledthe plankton

Plankton: A term used to describe small organisms found in lakes andoceans; the term includes heterotrophic plankton (usuallyinvertebrate animals) and autotrophic plankton (such as algae)

The region beneath the limentic zone, where there is not enough lightfor photosynthesis to occur, is called the profundal zone

Profundal Zone: The region beneath the limnetic zone of a lake,where there is no enough light to carry out photosynthesis

There are two types of lakes:Oligotrophic lakes are typically deep and coldEutrophic lakes are generally shallow and warmer


23/30

Oligotrophic: A term used to describe a lake that is deep, cold, andlow in dissolved nutrients; the water of such lakes is usually cold

Eutrophic: A term used to describe a lake that contains moredissolved nutrients than an oligotrophic lake; such lakes are generallyshallow and warm, and the water is often murky

The upper level of a lake, which warns up in the summer, is called theepilimnion

The lower level, which remains at a low temperature, is called thehypolimnion

Between these two level is the termocline, a narrows zone in whichthe temperature drops rapid from warm to cold

Epilimnion: The upper level of a lake, which warms up in the summer

Hypolimnion: The lower level of a lake, which remains cool even insummer

Termocline: A narrows zone in a lake between the epilimnion andhypolimnion in which the temperature drops rapidly form warm tocold

4.2 Sources of Water Pollution

Water pollution is any physical or chemical change in surface wateror ground water that can harm living things

Water pollution: Any change, whether physical or chemical, that isintroduced to surface water or ground water

Categories of Pollution:1) Organic Solid Waste; (Oxygen in water is used up as organicmatter is decomposed by bacteria. The decomposition may cause

foul odour)2) Disease-causing organism; (These organism can trigger anoutbreak of a waterborne disease, such as typhoid, cholera,infectious hepatitis, or dysentery)3) Inorganic solids and dissolved minerals; (This causes acid rain tooccur and damage organism that receive the precipitation. It alsoinduces algal bloom, which ruins aquatic ecosystems)4) Heat; (Industries draw on water to cool machinery or products andthen return warm water into the ecosystem. The addition of warmwater decreases the solubility of oxygen in the water)5) Organic Chemicals; (The toxins cause damage to organism

whether terrestrial or aquatic) The two main indicators of water quality are bacteria and dissolved

oxygen

Coliform Bacteria:

To narrow down the causes of low dissolved oxygen levels, it ispossible to test the biological oxygen demand (BOD)

BOD: A measure of the amount of dissolved oxygen needed bydecomposers (bacteria) to break down the organic matter in a


24/30

sample of water over a five-day period at 20C; used to indicate theamount of organic matter in a water sample

Too many nutrient can create problems for a lake

The greater the amount of decaying matter introduced into thewater, the greater will be the population of decomposing bacteria

In turn this causes oxygen levels to drop even more Which lowers the dissolved oxygen level within the lake

Another form of pollution is thermal population

Industries draw on water to cool machinery or products and thenreturn warm water into the ecosystem

The addition of warm water decreases the solubility of oxygen in thewater


Unit 4: Climate Change

7.1 Factors That Affect Climate Change

Atmosphere: A layer of gases that surrounds a planet or moon.

Climate: The characteristics pattern of weather conditions within aregion, including temperature, wind velocity, precipitation, and otherfeatures, averaged over a long period of time.

Greenhouse effect: The natural warming caused when gases in theEarths atmosphere absorb thermal energy that is radiated by theSun and Earth.

Hydrosphere: The collective mass of water found on, under, andover the surface of Earth in the form of liquid water, ice, and watervapour.

Albedo: The fraction of incident light or electromagnetic radiationthat is reflected by the surface of an object, such as from Earth backinto space; an objects ability to reflect sunlight.

Tectonic plate: A piece of Earths outer shell (the lithosphere) thatmoves around on the slowly flowing, underlying rock layer (theasthenosphere).

Anthropogenic: Relating to or resulting from the influence ofhumans.

Climate describes the standard weather conditions for a region at agiven time or year, including expected temperatures, winds,precipitation, probability of storms, and hours of direct sunshine.

The amount of energy that a location on the surface of Earth receivesat any given time is determined by the angle of the Sun, which inturn depends on the latitude, time of year, and time of day.

Winds, ocean currents, and the shape and size of continents affectclimate.


25/30

Earth reflects some of the solar energy that hits it back into space.The fraction of energy that is reflected by a surface is called albedo.

Volcanic eruptions introduce gases and particles into the air thataffect the reflection and absorption of energy from the Sun.

Human activity affects climate by introducing particles and gases into

the atmosphere that affect the absorption and transfer of energyfrom the Sun.

7.2 Describing Climates

Climatograph: A graph of climate data for a specific region; thedata is usually obtained over 30 years from observation made at localweather station.

Kppen climate classification system: A method of identifyingand describing climates based on observable features such astemperature ranges and rates of precipitation.

Biome:The largest division of the biosphere. Includes large regionsthat have similar biotic components (such as plants and an animals)and similar abiotic components (such as temperature and amount ofrainfall).

Ecozone: A division of the Earths surface that has developed over along period of time and is separated from neighbouring ecozones bygeological features such as an ocean, desert, or mountain range.

Ecoregion: A subdivision of an ecozone that is characterized by locallandforms such as plains, lakes, mountains, and rivers.

Climate zones can be classified based on latitude or on weatherfactors such as precipitation rates and temperature ranges.

Climatographs are useful tools for studying and comparing climates. Climate classification systems categorize the abiotic and biotic

components of a region and allow scientists to compare differentparts of the world easily.

Biomes are large regions that have similar types of organisms. Eachbiome is associated with a particular climate.

Ecozones and ecoregions are subdivisions of biomes that can be usedto compare the climate conditions in nearby or distant locations.

Some human activities, such as farming, depend on climate. Changesin climate may cause people living in different parts of the world tochange their lifestyles.

7.3 Indicators and Effects of Climate Change

Global warming: An increase in global average temperature.

Desertification: The process by which land slowly dries out untillittle or no vegetation can survive and the land becomes desert.

Deforestation: The destruction of the worlds forests through directhuman activity, such as logging or slash-and-burn clearing for


26/30

agriculture and grazing, and through the indirect effects of climatechange, pollution, and acid rain.

Global warming is the increase in the average temperature of theatmosphere and oceans over the past 100 years. It is the largestsingle indicator of recent climate change.

As global temperature rises, polar icecaps are melting, which affectsthe lives of Arctic mammals, such as polar bears, and of traditionalInuit peoples of Canada.

As atmospheric and ocean temperature increase, sea level is rising.Rising sea level will affect large population of humans who live onislands and along the coasts of the worlds continents.

As the global oceans absorb more carbon dioxide, the water becomesmore acidic, which threatens coral reefs and oceanic food chains.

Changes in wind and precipitation result from global warming. Thesechanges may lead to water shortage throughout the world andpossibly to more frequent and stronger storms.

Climate change may affect the health of humans by increasing theincidence of certain diseases.

Deforestation and desertification may result form highertemperatures and changes in precipitation.

8.1 Energy Transfer in the Climate System

System: A group of interdependent parts that work together to forma single functioning whole.

Feedback loop: A process in which part of a systems output isreturned, or fed back, to the input.

Electromagnetic radiation: Energy that travels as waves thatmove outward in all directions from a source; includes infraredradiation, ultraviolet radiation, radio waves, X rays, gamma rays, andvisible rays.

Thermohaline circulation: A three-dimensional pattern of oceancirculation driven by wind, heat, and salinity that is an importantcomponent of the ocean-atmosphere climate system.

Energy budget: A description of the total energy exchange within asystem; a summary of how energy from the Sun enters, movesthrough, and leaves the Earth system.

Earth is a system of interrelated parts, including atmosphere,

hydrosphere, rocks, and living things. The interrelated processes in the Earth system form a variety of both

positive and negative feedback loops, which affect the global climatesystem by increasing or decreasing the effects of climate change.

The atmosphere redistributes heat, energy, and moisture around theEarths surface.

Heat can be transferred by radiation, conduction, and convection.


27/30

Earths oceans transfer energy as water moves as a result of densitydifference that are caused by difference in the temperature andsalinity of ocean water.

El Nino and La Nina events are examples of the effects of heattransfer through the atmosphere and oceans.

To maintain a stable average global temperature, incoming energyand outgoing energy must balance each other exactly. This balanceis part of the Earths energy budget.

8.2 Greenhouse Gases and Human Activities

Concentration:The amount of a particular substance in a specificamount of another substance.

Parts per million (PPM): A unit of measurement that indicate thenumber of parts of substance per million parts of another substance;for example, for salt water, 1000 ppm of salt means 1000 parts saltin 1, 000, 000 parts of pure water.

Greenhouse gas: A gas in the Earths atmosphere that absorbs andprevents the escape of radiation as thermal energy; examplesinclude carbon dioxide and methane.

Sink: A process that removes greenhouse gases from theatmosphere.

Ozone: A greenhouse gas that is composed of three atoms ofoxygen; it is commonly found in a concentrated layer in thestratosphere.

Chlorofluorocarbons (CFC): A human-made chemical compoundthat contains chlorine, fluorine, and carbon; when released into the

atmosphere it may cause depletion of the ozone layer. Anthropogenic greenhouse effect: The increased capacity of the

atmosphere to absorb and prevent the escape of thermal energybecause of an increase in greenhouse gases introduced by humanactivities.

Global warming potential (GWP): The ability of a substance towarm the atmosphere by absorbing thermal energy.

Earth emits thermal energy. Greenhouse gases in the atmosphereabsorb this energy and radiate it in all directions. The thermal energythat returns to the Earth gives rise to the greenhouse effect.

Less than one gas molecule in a hundred is a greenhouse gas.

The most common greenhouse gas is water vapour. Other majorgreenhouse gases include carbon dioxide, methane, ozone, nitrousoxides, and halocarbons.

Human activities, such as agriculture and the burning of fossil fuelsare increasing the amounts of some of the greenhouse gases in theatmosphere.


28/30

An increase in greenhouse gases has resulted in the anthropogenicgreenhouse effect, which may be responsible for recent climatechange.

You can reduce your contribution of greenhouse gases by conservingelectricity, improving home-heating efficiency, and minimizing waste

as much as possible.

8.3 Cycling of Matter and the Climate System

Biogeochemical cycle: A natural process that exchanges matterand energy between the abiotic environment to the bioticenvironment and back.

Store: A part of a biogeochemical cycle in which matter or energyaccumulates, also called a reservoir.

Global carbon budget: The relative amount of carbon in differentstores; also an accounting of the exchanges (incomes and losses) ofcarbon between the stores of the carbon cycle.

Nitrogen Fixation: The process by which atmospheric nitrogen ischanged into forms that can be used by plats and other organisms.

Carbon and nitrogen cycle through living organisms quickly, but alsohave cycles that can store them in rocks for millions or billions ofyears.

Carbon had five main stores: living things, oceans, rocks, fossil fuels,and the atmosphere.

Human activities, such as the burning of fossil fuels, releases carbondioxide into the atmosphere, which may result in climate change.

Nitrogen fixation is the process by which atmospheric nitrogen is

changed into forms that can be used by plants and other organisms.It can be done by lightning, by bacteria, or by industry.

Human activities, especially the use of fertilizers for agriculture, haveincreased the amount of nitrogen in rivers, lakes, and oceans. Thisnitrogen causes algal blooms that result in dead zones in lakes andoceans.

9.1 Discovering Past Climates

Paleoclimatologist: A scientist who studies past climates on Earth.

Ice cores: A long cylinder of ice obtained by drilling into a glacier.

Isotope: Any of two or more forms of an element that have the same

number of protons but a different number of neutrons (for example,deuterium is an isotope of hydrogen.

Sedimentary rock: A type of rock that is formed by the depositionof sediment.

Fossil: The traces or remains of a once-living organism.


29/30

Paleoclimatologists reconstruct past climates by using the evidencethat the climate leave behind in the tree rings, ice, sedimentary rock,and fossils.

Tree rings can provide evidence about the growing conditions, suchas temperature and precipitation, during the lifetime of tree.

Ice cores can provide information about global temperature and thecomposition of the atmosphere for thousand of years in the past.

Scientists use chemical analyses of sediment cores form lakes andoceans to reconstruct past conditions of the atmosphere and thehydrosphere.

Rocks can provide information about the conditions that existedwhen they formed.

Fossils are remains of living things. Their distribution andcharacteristics provide clues about the climate at the time theorganism lived.

9.2 Monitoring and Modelling Climate Change Monitor: To measure conditions systematically and repeatedly inorder to track changes.

Geostationary: Describing a satellite that travels around theEarths equator at a speed that matches the speed of the Earthsrotation so that the satellite remains in the same position relative tothe Earths surface.

Climate model: A mathematical or computer program thatdescribes, simulates, and predicts the interactions of the atmosphere,oceans, land surface, and ice of the Earth to simulate past, present,

and future climate conditions General circulation model (GCM): A complex computerprogram that uses mathematical equations to describe the physicalprocesses of the atmosphere and to manipulate the variables thataffect how the natural climate system works.

Forcing agent: Any substance or process that alters the globalenergy balance and causes climate to change.

Dozens of satellites monitor the Earths climate, to providescientists with data to analyze changes in the Earth system and toproject changes in climate. Each satellite focuses on a differentaspect of climate and weather.

Scientists predict future climates by using computer simulations ofthe Earth

General circulation models (GCMs) are three-dimensional modelsthat represent how currents of water and air interact and movearound the planet over specified period of time.

The predictions of climate models are not 100 percent accuratebecause of imprecision in the data and difficulties in the calculations.


30/30

The major climate models agree on approximately how muchsome factors such as greenhouse gases contribute to climate change.However, the effects of other factors, such as clouds, are not as wellunderstood.

9.3 Taking Action to Slow Climate Change Bias: A tendency toward a particular perspective or point of view

that prevents objective assessment of a topic.

Carbon footprint:The effect that human activities have on theenvironment in terms of the amount of greenhouse gases produced,measured in units of carbon dioxide.

Carbon offset: A means of reducing or avoiding greenhouse gasemissions by purchasing credits to reduce your carbon footprint.

Educating yourself about the facts related to the issue of climatechange is important in making informed decisions about how youractions affect climate change.

Everybody has a carbon footprint, which means that everyonesactions influence the amount of greenhouse gases emitted into theatmosphere. As a result, everybody is responsible for reducinggreenhouse gas emissions.

You can reduce your carbon footprint by performing actions thatlower your dependence on burning fossil fuels and by purchasingcarbon offsets.

Governments and international panels are trying to reducegreenhouse gas emissions by passing laws, by educating consumers,and by using economic means to combat climate change.

everything notes

Documents