chapter introduction lesson 1 physical properties lesson 2 density

Chapter Introduction

Lesson 1 Physical Properties

Lesson 2 Density

Lesson 3 Solids, Liquids and Gases

Lesson 4 Chemical Properties

Lesson 5 Physical and Chemical Changes

Lesson 6 Chemical Reactions

Chapter Wrap-Up

What are the properties of different types of matter?

Essential Question

• How can we measure and describe the physical properties of matter?

Physical Properties

Matter

Atom

Physical property

Mass

Physical Properties

Weight

Volume

• Matter is anything that has mass and takes up space.

– Ex. Air, glass, water, cup.

• All have mass, all take up space.

– Non Ex. Light, heat, emotions, thoughts

• All do not have mass and do not take up space.

What is matter?

• The makeup of matter was a mystery to people for centuries until an ancient Greek philosopher Democritus first theorized about the atom.

• Atom is a small particle of an element that still has the same chemical properties of the element.

What is matter? (cont.)

– Atoms are tiny. Millions of atoms can fit in a space as small as this letter….i.

– Atoms can combine with other atoms to make molecules.

• Ex. Water

What is matter? (cont.)

• Physical properties a property that can be observed without changing the identity of substance.

– Ex. Color, odor

What are Physical Properties?

• All matter has physical properties. These properties help us tell substances apart.

– Mass is the amount of matter in an object.

• Measured in grams or kilograms (g or kg) with a balance.

What are Physical Properties? (cont.)

– Weight is the measurement of the pull of gravity on an object.

• Measured in newtons (N) with a spring scale.

• Weight depends on gravity, which can change depending on where the object is located.

Ex.

What are physical properties? (cont.)

Location Mass Weight

Earth 51kg 498.7N

Moon 51kg 124.7N

What are physical properties? (cont.)

– Volume is the amount of space matter takes up.

• Measured in millimeters (mL) using a graduated cylinder and in cm3 for solids.

• 1 cubic centimeter (cm3) is equal to 1 millimeter (mL).

What are physical properties? (cont.)

– Volume (cont.)

• To measure the volume of a regularly shaped solid, like a book, you measure the length, width and height and multiply them all together.

– Ex. length x width x height

• To measure the volume of an irregularly shaped object, you measure the amount of water that is moved out of the way or displaced when the object is put in water.

– Ex. Volume of water and object – volume of water alone

• Conductivity is the ability of a material to transfer heat and electricity.

• Malleability is the ability to be bent, flattened or hammered without breaking.

• Ductility is the ability to be pulled into thin wires without breaking.

• Hardness is the ability of the material to scratch another material.

What are other physical properties?

A. hardness

B. odor

C. color

D. beauty

1. Which is not a physical property used to identify substances?

A. mass

B. volume

C. weight

D. density

2. What is the amount of space a sample of matter occupies?

A. spring scale

B. graduated cylinder

C. balance

D. beaker

3. Which tool would be used to measure the mass of an object?

Essential Question

• What is density and how is it measured?

• GLE PS 2: Calculate the density of large and small quantities of a variety of substances (e.g., aluminum foil, water, copper, clay, rock)

Density

Density

Fluid

Density

• Density is the measurement of how much mass fits within a certain volume.

– Ex. Tennis ball and baseball (same size). Tennis ball floats in water while the baseball sinks in water. The tennis ball is less dense than the water and the baseball. The baseball is more dense (has more matter packed into the same volume of space) than the tennis ball and water.

– Measured in grams per cubic centimeter. (g/cm3)

What is density?

• Calculate the density of an object by dividing its mass by its volume.

Density (D) = mass (m)

volume (v)

– Ex. Volume = 73mL

mass = 80.3g

80.3 ÷ 73 = 1.1g/mL or g/cm3

What is density? (cont.)

• The density of a material depends on the masses of the particles that make up the material.

What does density depend on?

• The density of a material also depends on the distance between the particles in the material.

• Density is constant for a given substance, regardless of the size of the sample.

– Ex. A chocolate bar has a density of 1.2g/cm3. You break the bar into three different pieces. Every piece will have a density of 1.2g/cm3.

• Because density is unique for each substance, it can be used to help identify materials.

What does density depend on? (cont.)

• Liquids and gases are fluids.

• Fluid is a material that can flow and has no definite shape.

A. color

B. weight

C. volume

D. length

4. A student knows the mass of an object. What other variable does the student need to know to calculate the object’s density?

A. m x v

B. v/m

C. m/v

D. v - m

5. What is the formula for density?

A. density

B. volume

C. mass

D. weight

6. Which would be most useful for identifying an unknown liquid?

A. grams per cubic centimeters

B. grams per milliliters

C. pounds per milliliters

D. Both A & B

7. What is density measured in?

A. Density is a measurement of how much mass fits within a certain volume

B. Density is a physical property

C. The density of water is 1.0 g/mL

D. Density of an object changes when the mass changes.

8. Which of the following is not true?

Essential Question

• How does energy affect the properties of matter?

Solids, Liquids and Gases

Solid

Liquid

Gas

Temperature

Solids, Liquids and Gases

Melting point

Freezing point

Boiling point

• A state of matter is a form that matter can take.

• On Earth, there are three common states of matter: solid, liquid and gas.

• Scientists recognize another state of matter known as plasma.

– Plasma is found in stars, lightning and neon lights.

What are states of matter?

• All matter is made of tiny particles that are constantly moving.

• A solid is matter that has a definite shape and occupies a definite amount of space.

What are states of matter? (cont.)

- particles vibrate back and forth but do not move past one another. They “wiggle” in relatively fixed positions.

• A liquid is matter that takes up a definite amount of space but has no definite shape.

– In liquids, the distance between particles is greater than in solids and they can slide past one another.

What are states of matter? (cont.)

• A gas is matter that has no definite shape and does not take up a definite amount of space.

– In a gas, particles move freely rather than staying close together.

What are states of matter? (cont.)

• Recall that particles of matter are in constant motion.

– Their motion depends on the energy they possess.

How does heat affect the state of matter?

Moving objects possess a type of energy called kinetic energy.

– Particles with more kinetic energy move faster and farther apart.

– Particles with less kinetic energy move more slowly and stay close together.

How does heat affect the state of matter? (cont.)

• Not all the particles in a sample of matter have the same energy.

• Temperature is a measure of the average kinetic energy of the particles in a material.

• Matter can change from one state to another when energy is absorbed or released.

How does heat affect the state of matter? (cont.)

• When a substance changes from a solid to a liquid (melting) to a gas (vaporizing) – energy is being absorbed.

• When a substance changes from gas to a liquid (condensing) to a solid (freezing) – energy is being released.

How does heat affect the state of matter?

• The state of matter can change in other ways. Sublimation occurs when a substance changes directly from a solid to a gas without going through a liquid state.

– Ex. Dry ice – is solid carbon dioxide and at room temperature does not exist as a liquid but becomes a gas.

How does heat affect the state of matter? (cont.)

• A solid that is a pure substance has a characteristic (unique) melting point.

• Melting point the temperature at which the solid melts to become a liquid.

– Ex. Sugar melting point = 186°C

Salt melting point = 801°C

• Because the substances melt at different temperatures, knowing the temperatures at which they melt will help you identify which substance is table salt and which is sugar.

When does matter change states?

• As a substance is heated, it absorbs energy and its temperature rises.

• When the temperature reaches the melting point, the temperature stops increasing.

– At this point, the solid is changing into a liquid and all the energy is spent breaking particles apart from one another.

When does matter change states? (cont.)

• After the substance has changed into a liquid, adding energy (heat) causes the temperature to increase again.

– The temperature of the material decreases until the freezing point is reached.

• Freezing point the temperature at which a liquid changes into a solid.

– During freezing, the temperature of the substance remains constant while the particles in the liquid form a solid.

• After all the liquid has become a solid, the temperature begins to decrease again.

When does matter change states? (cont.) • The process of melting a solid can be reversed.

• As the liquid cools, it loses energy and its particles lose kinetic energy and slow down. They become closer together.

• Melting and freezing are opposite processes.

• The freezing point of the liquid state of a substance is the same temperature as the melting point of the solid state.

– Ex. Solid water melts at 0°C and liquid water freezes at 0°C

When does matter change states?(cont.)

• Remember that the change from a liquid to a gas is called vaporization.

• Vaporization can occur within a liquid and at the surface of a liquid.

– Vaporization that takes place at the surface of a liquid is called evaporation, which occurs at temperatures below the boiling point.

• Ex. Puddles drying up after it rains.

What is boiling point?

• Vaporization that occurs below the surface of a liquid is called boiling.

– When liquid boils, bubbles form within the liquid and rise to the surface.

What is boiling point? (cont.)

• Boiling point is the temperature at which a liquid becomes a gas.

• Just like melting and freezing, while a substance is boiling, the temperature does not change.

• At it’s boiling point, a substance absorbs energy and the energy causes the particles to move faster until they have enough energy to escape the liquid as gas particles.

What is boiling point? (cont.)

• Boiling ends after the liquid has changed to a gas. If energy continues to be added, then the temperature of the gas will continue to rise.

• The reverse of vaporization is condensation – a gas to a liquid.

• As the gas cools, energy is released and its particles slow down

– When particles move slowly enough for their attractions to bring them together, droplets of liquid form.

• During condensation, the temperature of the substance does not change

What is boiling point? (cont.)

• After the change of state is complete, the temperature continues to drop.

• Every substance melts and boils at specific temperatures.

• A material with high melting and boiling points has particles that are strongly attracted to one another.

• A material with low melting and boiling points has particles that are weakly attracted to one another.

What is boiling point? (cont.)

• Air pressure is the force exerted by a gas.

• Ex. Blowing up a balloon

– The air particles move around rapidly inside the balloon and hit the inner surface of the balloon, exerting pressure on the balloon.

– If you squeeze the balloon (increase the pressure), the balloon gets smaller (volume decreases).

What is air pressure?

Ex. Blowing up a balloon (cont.)

– If you put the balloon in the freezer (decrease temperature) and keep the pressure the same, the balloon gets smaller (volume decreases).

– If you allow the balloon to sit out and warm up (increase temperature) and keep the pressure the same, the balloon will get bigger (volume increases).

What is air pressure?

A. Its mass increases.

B. Its particles move more slowly.

C. Its particles move faster.

D. Its particles stop moving.

Which happens to an object as its temperature increases?

A. condensation

B. vaporization

C. boiling

D. melting

During which change of state do the particles in a material become closer?

Essential Question

• What properties determine how substances react with each other?

Chemical Properties

Chemical property

Reactivity

Acid

Base

Chemical Properties

Neutralization

• Chemical property is the way a substance reacts with other substances.

– Ex. When you put baking soda in vinegar. The baking soda reacts strongly with the vinegar, producing carbon dioxide gas.

• Reactivity is how easily something reacts with something else.

– Ex. Potassium and water = strong, violent reaction (highly reactive)

Copper and water = no reaction (not reactive)

What are chemical properties?

• Flammability is a chemical property of a substance that describes its ability to catch on fire or burn.

– After burning, the substance no longer exists. It has changed into ash and gases.

• Ex. Hydrogen and methane = highly flammable (easy to burn)

Rock and sand = not flammable (don’t burn)

What are chemical properties? (cont.)

• One way to describe matter is to classify it as an acid or a base.

– The pH scale measures the strengths of acids and bases. It runs from 0 to 14.

What are chemical properties of acids and bases?

• Acid a substance that has a pH below 7, tastes sour, makes blue litmus paper turn pink or red.

– Ex. Lemon juice, vinegar

– Acids also release hydrogen ions (H+) in solution.

– The higher the hydrogen ion concentration, the stronger the acid.

What are chemical properties of acids and bases?

• Base a substance that has a pH above 7, tastes bitter, makes red litmus paper turn blue.

– Ex. Baking soda, soap, antacids

– Bases release hydroxide ions (OH-) in solution.

– The higher the concentration of hydroxide ions, the stronger the base.

What are chemical properties of acids and bases? (cont.)

• Both strong acids and bases can burn skin.

• Neutralization is the chemical change of an acid and a base into water and a salt.

What are chemical properties of acids and bases? (cont.)

• Every substance has its own unique set of physical and chemical properties.

• All matter can be described using both types of properties

How do chemical and physical properties compare?

– Ex. The statue of liberty is made of copper. Because of copper’s reactivity to substances in the air, the Statue of Liberty is now green and not shiny like a penny.

A. flammable

B. fragile

C. handle with care

D. shake well

Which warning refers to a chemical property of the material?

A. density

B. mass

C. reacts with water

D. yellow powder

Which is a chemical property of a substance?

Essential Question

• How do physical and chemical changes to matter compare?

Physical and Chemical Changes

Physical change

Chemical change

Precipitate

Physical and Chemical Changes

• Physical change a change in size, shape or state that does not form a new substance.

– Ex. Tearing paper, sharpening a pencil, melting ice

• Combining two substances to form a mixture is another example of a physical change. The two substances do not lose their identities when combined. They can still be physically separated from each other to obtain original substances.

– Ex. Snack mix (Cereal, peanuts, pretzels all mixed together)

What are physical changes?

• Chemical change is a change in matter that produces a new substance with different properties from the original

– Ex. Baking a cake, frying an egg, rusting, burning paper

• Substances that undergo a chemical change no longer have the same properties because they no longer have the same identity.

– This is because the atoms in the substances that have formed are arranged differently from the original substances.

What are chemical changes?

• Color change

– Ex. Iron rusting – changes from gray to reddish brown

sliced apple turning brown

• Release or absorption of energy

– Could be in the form of light, heat or sound

• Ex. Glow stick gives off light as a chemical change occurs.

What are the signs of chemical change?

• Formation of bubbles and/or gas

– Ex. Antacid tablet in water

• Formation of precipitate

– Precipitate is a solid that sometimes forms when two liquids combine

These are just signs of chemical change not proof of chemical change.

What are the signs of chemical change? (cont.)

Physical change

• Can be reversed easily.

– Ice melted and refrozen

• Original substance can be brought back to their original state using physical means.

– Dissolve salt in water, evaporate water, left with salt

• Chemical properties stay the same before and after the change.

How do physical and chemical changes compare?

Chemical change• Cannot be reversed easily.

– burning wood to ash

• Cannot bring back original substance with physical means.

• Chemical properties of the new substance are different than the chemical properties of the original substance.

A. Formation of a yellow precipitate

B. Light is given off

C. Formation of bubbles

D. A color change

Suppose you mix baking soda and vinegar. What signs might indicate that a chemical change is occurring?

A. Water freezes and forms ice

B. Iron rusts

C. A puddle evaporates

D. A soda can is crushed

Which is an example of a chemical change?

Essential Question

• How does matter change chemically?

Chemical Reactions

Chemical bonds

Chemical reactions

Reactants

Products

Chemical Reactions

Chemical equation

Law of conservation of mass

• Recall that all matter is made up millions of particles called atoms.

– Ex. A single drop of water contains trillions of oxygen and hydrogen atoms

• When atoms attach to other atoms they form chemical bonds.

What happens during a chemical change?

• Chemical bond is a force that hold atoms together.

– Ex. In water, all the atoms are arranged the same way (two hydrogen atoms bonded to one oxygen atom). If this arrangement changes, the substance is no longer water. A new substance has formed with new physical and chemical properties.

What happens during a chemical change? (cont.)

• Chemical reactions a process that produces chemical change, resulting in new substances that have properties different from those of the original substances.

– Ex. Electrolysis of water

2H2O → 2H2 + O2

(water) (hydrogen gas) (oxygen gas)

What happens during a chemical change? (cont.)

• Remember that all substances are made of particles that move constantly.

• If the particles collide with enough energy, the bonds between the atoms can break.

– The atoms separate and rearrange, and new bonds can form.

What happens during a chemical change? (cont.)

• Chemical equation is a way to represent a chemical reaction by using symbols for the amounts of reactants and products in the change.

– Reactants an original substance at the beginning of a chemical reaction.

– Products are the substances that form as a result of the reaction.

What are chemical equations?

• Chemical equations can be written using words to name the reactants.

– Ex. hydrogen + oxygen → water

What are chemical equations? (cont.)

• Chemical equations can also be written using chemical formulas – a combination of chemical symbols and numbers that shows the number and types of atoms present.

– Ex. 2H2 + O2 → 2H2O

(hydrogen) (oxygen) (water)

• The small numbers written to the right of the atoms are called subscripts. They tell you the number of atoms.

What are chemical equations? (cont.)

• A chemical reaction does not create new matter, it only forms new bonds among existing bonds.

• Law of conservation of mass states that matter cannot be created or destroyed during a chemical reaction.

• The total number of each type of atom must be the same in the reactants and the products.

– Ex. 2H2 + O2 → 2H2O

(4 –hydrogen) (2 – oxygen) = (4 – hydrogen)

(2 – oxygen)

What is conservation of mass?

A. Substances change state.

B. Atoms rearrange to form matter with different properties.

C. The form of an object changes, but its type of matter stays the same.

D. Solids are separated using filters.

Which best describes a chemical change?

A. Breaking the shells.

B. Heating the eggs.

C. Mixing the egg yolks and the egg whites together.

D. Putting pepper onto the cooked eggs.

What causes a chemical reaction when you prepare scrambled eggs?

Visual Summary

Chapter Review

Standardized Test Practice

Matter is anything that has mass and takes up space. All types of matter have physical and chemical properties. These properties can change.

• All matter is made of atoms.

• Physical properties of matter include size, shape, texture, the ability to conduct heat and electricity and color.

Lesson 1: Physical Properties

Lesson 2: Density and Buoyancy

• Density is a physical property that measure the amount of matter in a given volume.

• Solid, Liquid and gas are three states of matter.

• A change in energy can change the state of matter.

Lesson 3: Solids, Liquids and Gases

• Chemical properties include ability to burn, acidity and ability to rust.

Lesson 4: Chemical Properties

• Some signs that might indicate chemical changes are the formation of bubbles and a change in color or energy.

Lesson 5: Physical and Chemical Changes

• The law of conservation of mass states that mass before and after a chemical change is equal.

Lesson 6: Chemical Reactions

A. They move in circles.

B. They are always moving.

C. They are larger in solids than in liquids or gases.

D. They do not move in solids.

Which best describes the particles in matter?

A. melting and vaporization

B. freezing and boiling

C. condensation and melting

D. sublimation and freezing

During which processes must energy be added to a material?

A. 1.0 g/cm3

B. 0.11 g/cm3

C. 8.94 g/cm3

D. 10 g/cm3

A price of copper has a volume of 10.0cm3. If the mass of the copper is 89.4g. What is the density of copper?

A. solid

B. gas

C. liquid

D. plasma

In which state of matter are particles close together yet able to move past one another?

A. Acids and bases

B. Bases and gases

C. Solids and gases

D. Acids and solids

Salts are formed when which react?

A. water

B. gas

C. matter

D. a solid

What term describes anything that has mass and takes up space?

A. volume

B. color

C. mass

D. density

Depending on the size and shape of its container, a gas changes both shape and which of the following?

A. physical change

B. conservation of mass

C. chemical change

D. physical and chemical change

Which refers to a change in a substance where no new substances are formed?

A. a gas

B. a new liquid

C. a solid

D. a precipitate

When a substance is heated to its boiling point, the bubbles indicate that liquid is turning into which of these?

A. melting

B. boiling

C. physical reaction

D. chemical reaction

What is another name for a chemical change?