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Basic Chemistry Basic Chemistry

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Page 1: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Basic ChemistryBasic Chemistry

Page 2: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

The Nature of MatterThe Nature of Matter

MatterMatter refers to anything that takes up refers to anything that takes up space and has mass.space and has mass.

Matter is composed of elements, Matter is composed of elements, substances that cannot be broken down substances that cannot be broken down into another substance.into another substance.There are 92 natural elements.There are 92 natural elements.Living organisms are made primarily of six Living organisms are made primarily of six

elements.elements.

Page 3: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

The Nature of MatterThe Nature of Matter

Page 4: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

The Nature of MatterThe Nature of Matter

Elements:Elements:Made up of tiny particles called Made up of tiny particles called

atomsatomsEach has its own Each has its own

name name atomic number atomic number atomic symbolatomic symbol

Name Number Symbol

Hydrogen 1 H

Aluminum 13 Al

Sodium 11 Na

Page 5: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Atomic StructureAtomic Structure

Atoms have three main sub atomic Atoms have three main sub atomic structuresstructures::

Name Charge Mass LocationName Charge Mass Location

ProtonProton + 1 amu inside nucleus + 1 amu inside nucleus

Electron - 1/1837 amu around nucleusElectron - 1/1837 amu around nucleus

Neutron o 1 amu inside nucleusNeutron o 1 amu inside nucleus

Page 6: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Atomic StructureAtomic Structure

All atoms of the same All atoms of the same element have the same element have the same

number of protonsnumber of protons

It is also equal to the atomic It is also equal to the atomic numbernumber

Page 7: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

The Periodic TableThe Periodic Table

The elements are organized to form the The elements are organized to form the periodic tableperiodic table..The columns in the table are groups.The columns in the table are groups.The rows in the table are periods.The rows in the table are periods.

Elements in groups have similar chemical Elements in groups have similar chemical and physical characteristics.and physical characteristics.

Page 8: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

The Periodic TableThe Periodic Table

Page 9: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Atomic StructureAtomic Structure

The The Atomic MassAtomic Mass is the number of is the number of

protons and neutronsprotons and neutrons

Na23

11

Mass

Atomic Number

Number of protons: 11

Number of neutrons: 12

(23 – 11)

Number of electrons 11

Page 10: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Composition of Matter- ElementsComposition of Matter- Elements

Symbols to know:Symbols to know:

C Carbon Na Sodium Mg Magnesium C Carbon Na Sodium Mg Magnesium

O Oxygen P Phosphorus Fe Iron O Oxygen P Phosphorus Fe Iron

H Hydrogen S SulfurH Hydrogen S Sulfur Ca CalciumCa Calcium

N Nitrogen Cl Chlorine K PotassiumN Nitrogen Cl Chlorine K Potassium

Page 11: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Composition of Matter- ElementsComposition of Matter- Elements

IsotopesIsotopes

Many elements have isotopes. Many elements have isotopes.

Isotopes have the Isotopes have the same atomic numbersame atomic number

but a but a different atomic massdifferent atomic mass

(they have more or less neutrons)(they have more or less neutrons)

Page 12: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Composition of Matter- ElementsComposition of Matter- Elements

Isotopes are represented differently, showing Isotopes are represented differently, showing their atomic mass.their atomic mass.

Examples: Examples:

carbon – 14carbon – 14 is an isotope of carbon with a is an isotope of carbon with a mass of 14 (the normal mass is 12) mass of 14 (the normal mass is 12)

iodine – 131iodine – 131 is an isotope of iodine with a is an isotope of iodine with a mass of 131 (the normal mass is 127) mass of 131 (the normal mass is 127)

Page 13: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Composition of Matter- ElementsComposition of Matter- Elements

Certain isotopes are very unstable and Certain isotopes are very unstable and release energy as they “fall apart” or release energy as they “fall apart” or disintegrate. disintegrate.

These isotopes are called These isotopes are called radioactive radioactive isotopesisotopes or radioisotopes. or radioisotopes.

This radiation can be detected with a This radiation can be detected with a Geiger counter.Geiger counter.

Page 14: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Uses of Radioactive IsotopesUses of Radioactive Isotopes

Radioactive isotopes can be used as Radioactive isotopes can be used as tracerstracers to follow the movement of that to follow the movement of that element.element.

Radioactive isotopes can be used to Radioactive isotopes can be used to sterilize medical and dental instruments.sterilize medical and dental instruments.

Radioactive isotopes can also be used to Radioactive isotopes can also be used to kill cancer cells.kill cancer cells.

Page 15: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Uses of Radioactive IsotopesUses of Radioactive Isotopes

Page 16: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Atomic StructureAtomic Structure Electrons are found in energy levels outside the Electrons are found in energy levels outside the

nucleusnucleus

The first energy level holds two electronsThe first energy level holds two electrons The second energy level holds eight electronsThe second energy level holds eight electrons

The third energy level holds eight electronsThe third energy level holds eight electrons Other levels can hold moreOther levels can hold more

Octet RuleOctet Rule: Stable atoms have eight electrons : Stable atoms have eight electrons in their outer level in their outer level

Page 17: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Atomic StructureAtomic Structure

Electrons in the outermost shell are called Electrons in the outermost shell are called valence electronsvalence electrons

All elements in the same column (group) All elements in the same column (group) of the Periodic table have the same of the Periodic table have the same

number of valence electronsnumber of valence electronsThe valence electrons determine how an The valence electrons determine how an

element will reactelement will react

Page 18: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Arrangements of Electrons in an Arrangements of Electrons in an AtomAtom

Page 19: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Chemical BondsChemical Bonds

A group of atoms bonded to one another A group of atoms bonded to one another form a form a moleculemolecule..

If the molecule has more than one type of If the molecule has more than one type of element present it is a element present it is a compoundcompound..

Different types of Different types of bondsbonds hold molecules hold molecules and compounds together.and compounds together.

Page 20: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Chemical FormulasChemical Formulas

Types of FormulasTypes of Formulas

Molecular formulas show the actual Molecular formulas show the actual composition of a compound using symbols composition of a compound using symbols

of elements and their proportionsof elements and their proportions

Examples: Examples:

Water Methane Carbon dioxide Water Methane Carbon dioxide

HH22O CHO CH4 4 CO CO22

Page 21: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Chemical FormulasChemical Formulas

Structural formulas are formulas that show Structural formulas are formulas that show the bonding of elements in a compound the bonding of elements in a compound

and their relative positionsand their relative positions

Examples: Examples:

Water Methane Carbon dioxideWater Methane Carbon dioxide

H H OH H O

H C HH C H

H OH O H H C O C O

Page 22: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Composition of Matter - CompoundsComposition of Matter - Compounds

Chemical BondsChemical Bonds

A chemical bond is the “glue” that holds the A chemical bond is the “glue” that holds the elements together in compounds.elements together in compounds.

The valence electrons determine how an The valence electrons determine how an element will react and bondelement will react and bond

Page 23: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Types of Chemical BondsTypes of Chemical Bonds Charged atoms, or Charged atoms, or ionsions, can form when atoms , can form when atoms

lose or gain electrons.lose or gain electrons. Atoms that lose an electron become PositiveAtoms that lose an electron become Positive Atoms that gain electrons become NegativeAtoms that gain electrons become Negative

Positive and negative ions are attracted to one Positive and negative ions are attracted to one another and bond together in another and bond together in ionic bondsionic bonds..

Usually between a metal and non metal that are Usually between a metal and non metal that are far apart horizontally on the periodic table.far apart horizontally on the periodic table.

A A saltsalt is a dry solid composed of atoms is a dry solid composed of atoms connected by ionic bonds.connected by ionic bonds.

Page 24: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Types of Chemical BondsTypes of Chemical Bonds

Ionic Bonds

Sodium (one valence electron)

Loses the electron

Becomes positive (+)

Chlorine (seven valence electrons)

Gains the electron

Becomes negative (-)

Opposites Attract!

Each outer shell has eight electrons

Page 25: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Types of BondsTypes of Bonds

formed when electrons are formed when electrons are sharedshared among among elements in a compound.elements in a compound.

usually formed between two non metals or usually formed between two non metals or a non metal and hydrogena non metal and hydrogen

Models or diagrams can be drawn to show Models or diagrams can be drawn to show the shared electrons the shared electrons

Covalent bondsCovalent bonds

Page 26: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Types of Chemical BondsTypes of Chemical Bonds

Page 27: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Chemical EquationsChemical EquationsEquationsEquations show the: show the:chemicals that are reactingchemicals that are reactingproducts that are madeproducts that are madeamount of each chemical involvedamount of each chemical involved

In equations, In equations, reactantsreactants are on the left are on the left the the productsproducts are on the right. are on the right.

Example:Example:

Water produces hydrogen and oxygenWater produces hydrogen and oxygen

2H2H22O 2HO 2H22 + O + O22

Page 28: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Chemical ReactionsChemical Reactions

Molecules that participate in a reaction are Molecules that participate in a reaction are reactantsreactants..

Molecules formed by a reaction are Molecules formed by a reaction are productsproducts..

6 CO2 + 6 H2O C6H12O6 + 6 O2

carbondioxide

water oxygenglucose

The chemical reaction for photosynthesis

Page 29: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pH

DissociationDissociation occurs when an ionic occurs when an ionic compound separates into its compound separates into its

ions.ions.

Example:Example:Salt (NaCl) breaks apart into Na+ Salt (NaCl) breaks apart into Na+

and Cl-and Cl-

Na+ Cl-

Page 30: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Acids and BasesAcids and Bases

When water dissociates, it releases an When water dissociates, it releases an equal number of ions.equal number of ions.Hydrogen ions (HHydrogen ions (H++))Hydroxide ions (OHHydroxide ions (OH--))

H – O – H H+ + OH-

Page 31: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pH

AcidsAcidsAcids will dissociate in Acids will dissociate in

water to release a water to release a hydrogen ion (H+)hydrogen ion (H+)

Examples:Examples:

HClHCl HH22SOSO44

HCHC33HH55OO33

(Notice the H at the front of the formula)(Notice the H at the front of the formula)

Page 32: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pHBases will dissociate Bases will dissociate

in water and release in water and release OH- (hydroxyl) ionsOH- (hydroxyl) ions

They have a low They have a low concentration of H+concentration of H+

Examples: Examples:

NaOH KOHNaOH KOH(notice they end in –OH)(notice they end in –OH)

Page 33: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

pH and the pH scalepH and the pH scale

The The pHpH is a mathematical way of is a mathematical way of indicating the number of Hindicating the number of H++ ions in a ions in a solution. solution.

The lower the number, the higher the The lower the number, the higher the concentration.concentration.

The The pH scalepH scale is used to express acidity or is used to express acidity or basicity (alkalinity).basicity (alkalinity).

Page 34: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pHAcids have a low pH (less than 7) and bases Acids have a low pH (less than 7) and bases

have a high pH (more than 7)have a high pH (more than 7) 1 7 141 7 14

Strong Strong Neutral Neutral StrongStrong

Acid BaseAcid Base

The farther away from neutral, the stronger The farther away from neutral, the stronger the acid or base.the acid or base.

Page 35: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pH

Extremely acidic: Extremely acidic: lemon=2.5; vinegar=3.0; stomach acid=2.0lemon=2.5; vinegar=3.0; stomach acid=2.0 Very strongly acid:Very strongly acid: tomatoes=4.5 tomatoes=4.5 Strongly acid:Strongly acid: carrots=5.0; asparagus=5.5; cabbage=5.3 carrots=5.0; asparagus=5.5; cabbage=5.3 Moderately acid:Moderately acid: potatoes=5.6 potatoes=5.6 Slightly acid:Slightly acid: salmon=6.2; cow's milk=6.5 salmon=6.2; cow's milk=6.5 Neutral:Neutral: saliva=6.6–7.3; blood=7.3; shrimp=7.0 saliva=6.6–7.3; blood=7.3; shrimp=7.0 Slightly alkaline:Slightly alkaline: eggs=7.6–7.8 eggs=7.6–7.8 Moderately alkaline:Moderately alkaline: sea water=8.2; sodium bicarbonate=8.4 sea water=8.2; sodium bicarbonate=8.4 Strongly alkaline:Strongly alkaline: borax=9.0 borax=9.0 Very strongly alkaline:Very strongly alkaline: milk of magnesia=10.5, ammonia=11.1; milk of magnesia=10.5, ammonia=11.1;

Page 36: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Water, Acids, Bases and pHWater, Acids, Bases and pHMixing an acid with a base a chemical Mixing an acid with a base a chemical

reaction will change the pH of the mixturereaction will change the pH of the mixtureHydrogen ions will react with the hydroxyl Hydrogen ions will react with the hydroxyl

ions and form waterions and form water

H H ++ + OH + OH- - HOH HOH If the ions are in equal amounts, the If the ions are in equal amounts, the

mixture becomes neutral (pH 7)mixture becomes neutral (pH 7)This is called a This is called a neutralizationneutralization reaction. reaction.The remaining ions form a salt.The remaining ions form a salt.

Page 37: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Buffers and pHBuffers and pH

Within the body, the pH is kept in a narrow Within the body, the pH is kept in a narrow range to maintain health. range to maintain health.

A A bufferbuffer is a chemical or combination of is a chemical or combination of chemicals that keeps a pH within a given chemicals that keeps a pH within a given range. range.

Buffers resist changes in pH by taking up Buffers resist changes in pH by taking up extra Hextra H++ or OH or OH-- from solution. from solution.

Page 38: Basic Chemistry. The Nature of Matter Matter refers to anything that takes up space and has mass. Matter refers to anything that takes up space and has

Buffers and pHBuffers and pH