lesson 2 | matter and its changes - ms. holm science -...

Name Date Class

LESSON 2

Matter and Its ChangesA. Changes of Matter

1. Matter changes with the season, including changes in the of leaves and in the ofthe air.

2. Matter can change in many ways, including changesand changes.

B. What are physical changes?

1. In a physical change, the of the substance does notchange.

2. one substance in another does not change theidentities of the substances.

3. The formation of ice on the surface of a lake is an example ofa(n) .

4. Changes in state involve changes in the amount of thatthe particles in a substance have.

5. The at which one state of matter changes into anotherdepends on how much energy is added or taken away from the substance.

C. What are chemical changes?

1. In a chemical change, the substances that make up matter change into othersubstances with physical properties and chemicalproperties.

2. Changes in , density, and state of matter can be signs ofa chemical change.

3. The formation of a(n) substance is the only sure sign ofa chemical change.

a. Formation of a(n) might be signaled by bubbles or anodor.

b. Formation of a(n) , a solid that sometimes formswhen two liquids combine, is a sign of a chemical change.

c. A change in might or might not be a sign of achemical change. It depends on whether a(n) forms.

Matter: Properties and Changes 29

Lesson Outline

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Lesson Outline continued

4. Energy is a sign that chemical change is involved.

5. Energy in the form of is needed for chemical reactionssuch as photosynthesis.

6. is a chemical reaction that only occurs if plants areexposed to light.

7. Many changes cannot be .

8. is always conserved during physical and chemicalchanges.

9. The law of conservation of mass states that the total mass before a(n)

is the same as the total mass after it.

10. The mass of an unburned match plus the mass of the oxygen it reacts with

the mass of the ashes and of all the gases given off

when the match burns.

D. Comparing Physical and Chemical Changes

1. Changing the shape of a piece of clay is a(n) change.

2. Spoiling foods are examples of change.

30 Matter: Properties and Changes

Name Date Class

LESSON 2

Matter and Its ChangesDirections: Complete this chart by choosing terms from the word bank and writing them in the correct spaces.

boiling burning chemical changes dissolvingmelting photosynthesis rusting

Directions: Circle the term in parentheses that correctly completes each sentence.

8. When matter undergoes a physical or chemical change, the amount of mass(changes/stays the same).

9. All chemical reactions result in the production of a new substance and involve achange in (energy/volume).

10. Some changes cannot be (repeated/reversed).

11. Photosynthesis is an example of a (physical/chemical) change that almost all livingthings rely on.


Content Practice A

Changes to Matter

examples examples

Physical changes

1.

2.

3.

5.

6.

7.

4.

Name Date Class

LESSON 2

Matter and Its ChangesDirections: Complete each item on the lines provided.

1. What is a physical change in matter?

2. All changes in the of matter are physical changes.

3. What is a chemical change in matter?

4. Name three signs of a chemical change that are mentioned in the lesson.

5. What is the only sure sign of a chemical change?

6. What kind of energy do plants need to perform photosynthesis?

7. What happens to the total amount of mass during a physical or chemical change?

Directions: Tell whether the following changes are physical (P) or chemical (C) and whether they arereversible (R) or nonreversible (N).

8. iron rusting

9. salt dissolving

10. water freezing

11. wood burning

12. pottery shattering


Content Practice B

Name Date Class

LESSON 2

Word Building Activity: Sentence CompletionDirections: Study the terms and definitions below. Then write the term that correctly completes each sentence.Each term is used only once.

boiling point n. temperature at which a liquid changes to a gas

chemical property n. the ability or inability of a substance to combine with or changeinto one or more new substances

density n. the mass per unit volume of a substance

melting point n. temperature at which a solid changes to a liquid

physical change n. any change in matter in which the identity of the matter isnot changed

physical property n. any characteristic of a substance that can be observed withoutchanging the substance

solubility n. the ability of one material to dissolve in another

1. The of a material is the same, despite the size or amountof the material.

2. When an ice cube melts and becomes a liquid, it undergoes a

because the process does not change the composition of

the matter.

3. Water turns into a gas when it is heated to 100°C because that temperature is

its .

4. It takes a lot of energy to change solid steel into a liquid, because the of steel is 1,370°C.

5. One well-known of diamonds is hardness.

6. Sugar dissolves quickly in tea because it has a high inwater.

7. Objects made of iron can rust, which is a of the metal.


Language Arts Support

Name Date Class

LESSON 2

Matter and Its ChangesKey Concept How are physical changes different from chemical changes?

Directions: On the line before each change, write P for physical or C for chemical.

1. glass melting

2. wood burning

3. bread baking

4. water vapor condensing

5. iron rusting

6. leaves changing color

7. sugar dissolving

8. oxygen becoming liquid

9. silver tarnishing

Directions: Some changes can be reversed—others cannot. Put a check mark on the line before each change thatis reversible. Put an X on the line before each change that is not reversible.

10. making water into ice

11. hard-boiling an egg

12. dissolving salt in water

13. breaking a window

14. scorching a fabric


Key Concept Builder

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LESSON 2


Directions: Complete these diagrams by choosing terms from the word bank and writing them in the correctspaces.

burns evaporates heat ice lightspark sunlight vapor water wood

Directions: Complete each item below.

11. Put a star next to the words above that are sources of energy or the release of energy.

12. Ice must absorb heat to melt into water. What must water do to evaporate?


Key Concept Builder

Physical Chemical

1.

2.

3.

7.

6.

10.

9.

8.

5.

4.

and

producing

which

ignites

to become a

which later

into

melts

Name Date Class

LESSON 2


Directions: Work with a partner. Tell which signs of a chemical change occur with each of the processes below.

1. a log burning

2. photosynthesis

3. oxidation of silver

Directions: Complete each item below with your partner.

4. Another name for a chemical change is a(n) .

5. Respiration is a chemical change that occurs inside your body. What gas do you releaseevery time you exhale?


Many signs indicate that substances have undergone a chemical change rather thana physical change. These signs show that a new substance has been formed from achemical reaction.Three signs of a chemical change are

• changes in color,• the release of a gas, and• the formation of a new solid substance, such as a precipitate.

Key Concept Builder

Name Date Class

LESSON 2

Matter and Its ChangesKey Concept How do physical and chemical changes affect mass?

Directions: Complete each item below on the lines provided.

1. The principle that mass is never lost in physical and chemical changes is known as the

law of .

2. The ashes left by a forest fire don’t weigh as much as the trees did. Knowing that massis never destroyed, explain what happened to some of the mass of the trees as theyburned.

3. When water freezes, it expands in volume by 10 percent. If you froze 200 g of water,what would be the mass of the resulting block of ice? Explain your answer.

4. What happens to the mass of a soft drink when you open it?

5. If you could put a sealed room on a very sensitive scale and open a thousand soft drinkcans inside it, would the mass reading on the scale go up, go down, or stay the same?Explain your answer.


Key Concept Builder

Lesson 2: Matter and Its ChangesA. Changes of Matter

1. Matter changes with the season, including changes in the color of leaves and in the temperature of the air.

2. Matter can change in many ways, including physical changes and chemical changes.B. What are physical changes?

1. In a physical change, the identity of the substance does not change.2. Dissolving one substance in another does not change the identities of the substances.3. The formation of ice on the surface of a lake is an example of a(n) change in state.4. Changes in state involve changes in the amount of energy that the particles in a substance

have.5. The rate at which one state of matter changes into another depends on how much energy is

added or taken away from the substance.C. What are chemical changes?

1. In a chemical change, the substances that make up matter change into other substances with different physical properties and chemical properties.

2. Changes in color, density, and state of matter can be signs of a chemical change.3. The formation of a(n) new substance is the only sure sign of a chemical change.

a. Formation of a(n) gas might be signaled by bubbles or an odor.b. Formation of a(n) precipitate, a solid that sometimes forms when two liquids combine,

is a sign of a chemical change.c. A change in color might or might not be a sign of a chemical change. It depends on

whether a(n) new substance forms.4. The release of thermal energy is a sign that chemical change has occurred.5. Energy in the form of light is needed for chemical reactions such as photosynthesis.6. Photosynthesis is a chemical reaction that only occurs if plants are exposed to light.7. Many changes cannot be reversed.8. Mass is always conserved during physical and chemical changes.9. The law of conservation of mass states that the total mass before a(n) chemical reaction is the

same as the total mass after it.10. The mass of an unburned match plus the mass of the oxygen it reacts with equals the mass of

the ashes and of all the gases given off when the match burns.D. Comparing Physical and Chemical Changes

1. Changing the shape of a piece of clay is a(n) physical change.2. Spoiling foods are examples of chemical change.

Content Practice A (page 32)1–3. (in any order) dissolving, melting, boiling4. Chemical changes5–7. (in any order) burning, rusting, photosynthesis8. stays the same9. energy10. reversed11. chemical

Content Practice B (page 33)1. a change in which the identity of the material stays the same2. state3. a change in matter in which the substances that make up the matter change into other substances that have different chemical and physical properties4. formation of a gas, formation of a precipitate, change in color5. a change in energy6. light energy, usually in the form of sunlight7. It stays the same (or it is conserved).8. C, N9. P, R10. P, R11. C, N12. P, N

Language Arts Support (page 34)1. density2. physical change3. boiling point4. melting point

5. physical property6. solubility7. chemical propertyKey Concept Builder (page 37)1. P2. C3. C4. P5. C6. C7. P8. P9. C10. check mark11. X12. check mark13. X14. X

Key Concept Builder (page 38)1. spark2. wood3. burns4. heat5. light6. sunlight7. ice8. water9. evaporates10. vapor11. stars next to spark, sunlight, heat, light12. absorb even more heat

Key Concept Builder (page 39)1. the creation of ashes and release of carbon dioxide and water vapor2. the release of oxygen and production of sugars3. the silver tarnishes to a dull, gray color4. chemical reaction5. carbon dioxide

Key Concept Builder (page 40)1. conservation of mass2. Some of the mass of the trees is converted to carbon dioxide and other gases.3. 200 g; the mass of the water does not change. The water expands and becomes less dense.4. It decreases slightly, because it gives up carbon dioxide.5. The mass of the room would stay the same because all the gas released by the beverages would be contained within the room.

lesson 2 | matter and its changes - ms. holm science -...

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