Ch. 2 Physical Science study guide - Properties of Matter

Before clay is baked, it is soft and can be molded. After clay is baked, it is hard and brittle.

Use Table 2-3 to compare the physical properties of clay before and after it is baked at a high temperature.

Mixture B is a solution and all the particles would pass through a filter. Distillation might be used to separate the substances in Mixture B.

What is a possible reason why Mixture B in Figure 2-2 can't be separated by filtration? What method might be used to separate the substances in Mixture B?

Baked clay; it is brittle and shatters.

Which of the materials described in Table 2-3 would be least likely to be recycled? Explain your choice.

wax, unbaked clay, and metal

Which of the materials in Table 2-3 are malleable?

Mixture B; it does not scatter light, does not separate into layers, and cannot be separated by filtration.

Which of the mixtures in Figure 2-2 is a solution? Explain how you know.

Mixture C; it separates into layers and it can be separated by filtration.

Which of the mixtures in Figure 2-2 is a suspension? Explain how you know.

The object would have been made from wax because wax has a low melting point. It is the only material listed that would soften enough in a sunny window to change shape.

You have an object made from one of the materials listed in Table 2-3. It changes shape when you leave it in a sunny window. Which material is the object made from? How do you know?

What are three common clues that a chemical change has occurred?

a change in color, the production of a gas, and the formation of a precipitate

Which of the following is a clue of a chemical change?

a gas forms when vinegar and baking soda are mixed

Which of the following is a heterogeneous mixture?

a jar of mixed nuts

A material that is malleable and conducts electricity is most likely

a metal

If an unknown substance CANNOT be broken down into simpler substances, it is

an element. AND made of one kind of atom.

An element has a fixed composition because it contains only one type of ____________________.

atom

Water is a compound because it

can be broken down into simpler substances and always has two hydrogen atoms for each oxygen atom

A cake rises as it bakes because a chemical change causes ____________________ to be produced.

carbon dioxide

Which of the following is NOT a clue that a chemical change has occurred?

change in shape

When a physical change in a sample occurs, which of the following does NOT change?

composition

If a material contains three elements joined in a fixed proportion, it is a(an)

compound

A compound can be made from two or more elements or other ____________________ joined together in a fixed composition.

compounds

Which of the following are pure substances?

compounds

Which of the following has the highest viscosity?

corn syrup

What method can be used to separate parts of a liquid mixture when the entire mixture can pass through a filter?

distillation

What physical properties of nylon and leather make them good materials to use for shoelaces?

durability and flexibility

A substance that has high reactivity

easily combines chemically with other substances

A substance that is made up of only one kind of atom is a(an)

element

Which of the following is malleable?

gold

Which of the following is a characteristic of a mixture?

has varying properties

In a(an) ____________________ mixture, the parts of the mixture are noticeably different from one another.

heterogeneous

The substances in a(an) ____________________ mixture are evenly distributed throughout the mixture.

homogeneous

A mixture that appears to contain only one substance is a(an)

homogeneous mixture.

During which of the following chemical changes does a precipitate form?

lemon juice is added to milk

Which of the following is NOT a pure substance?

milk

Flammability is a material's ability to burn in the presence of

oxygen.

A(An) ____________________ change occurs when a material changes shape or size but the composition of the material does not change.

physical

A solid that forms and separates from a liquid mixture is a(an) ____________________.

precipitate

Rust forms because iron and oxygen are highly ____________________ elements.

reactive

Which of the following is a mixture?

sand

Which of the following is a physical change?

sawing a piece of wood in half

A mixture can be classified as a solution, suspension, or colloid based on the

size of its largest particles.

You are about to open a container of soy milk but notice that there are instructions to "shake well before serving." The soy milk is most likely a

suspension.

Filtration can be used to separate mixtures based on

the size of their particles.

How is a chemical change different from a physical change?

A chemical change involves a change in the composition of matter. During a physical change, the composition of matter does not change.

How can you change the properties of a mixture?

Accept any of the following: by adding more of one substance in the mixture; by adding a new substance; by removing a substance from the mixture.

What is the symbol for aluminum?

Al

The symbol for gold is

Au

A heterogeneous mixture; the mixture scatters light, separates into layers, and can be separated by filtration.

Based on the data in Figure 2-2, is Mixture C a homogeneous or heterogeneous mixture? Explain your answer.

melting, boiling

Based on the information in Figure 2-1, the ____________________ point of gold is 1064.2ºC and the ____________________ point of gold is 2856.0ºC.

hydrogen and nitrogen

Based on the information in Figure 2-1, which substances would be gases at 0ºC?

Both sculptures would be hard and would only melt at very high temperatures. The metal sculpture might be dented if it was hammered, but if the sculpture made from baked clay was hammered, it would shatter.

Based on the information in Table 2-3, compare the properties of a sculpture made from metal and a sculpture made from baked clay.

____________________ is a process that could be used to separate dissolved particles from the liquid in a solution.

Distillation

Suppose you want to separate the leaves, acorns, and twigs from a pile of soil. Filtration and distillation are two processes of separating mixtures. Explain which process you would use and why.

Filtration would be used because it is the process of separating mixtures based on the size of their particles (or pieces). A screen could be used to separate the mixture. The holes in the screen would need to be large enough to allow the soil to pass through but not the leaves, acorn, or twigs.

Mixture B, Mixture A, Mixture C

Rank the mixtures in Figure 2-2 in order of the size of their particles, starting with the mixture with the smallest particles.

Explain how you could use a physical property to test the purity of a silver coin without damaging the coin.

Silver has a known density at room temperature (10.5 g/cm3). You can measure the density of the coin and compare it to the density of silver. If the densities of the coin and silver are the same, the coin is pure silver. If the densities of the coin and silver are different, the coin either does not contain silver or contains at least one other substance in addition to silver.

How is the composition of a substance different from the composition of a mixture?

The composition of a substance is fixed, while the composition of a mixture can vary.

Which of the following is a chemical change?

water breaking down into hydrogen and oxygen

A substance has a melting point of 0ºC and a boiling point of 100ºC. The substance is most likely

water.

Which of the following materials is useful for making molds because it has a low melting point?

wax