Matter Practice Test

Which procedure BEST measures a physical property of a salt cube?

• A. Put the sample in water and watch for rust.

• B. Hold a piece in a flame to see if it burns.

• C. Measure its sides, calculate volume, find mass, and divide mass by volume for density.

• D. Add vinegar to a beaker, drop in the sample, and record what happens.

Answer explanation

Choice C is correct because measuring the sides and calculating volume, then finding mass to determine density directly assesses a physical property of the salt cube, unlike the other options which test for chemical reactions.

A student investigates a property of a salt block.

Part B: Which statement explains the investigation?

• The property tested is combustibility; the procedure checks if the sample burns when exposed to a flame.

• The property tested is reactivity; the procedure checks if the sample changes when mixed with oxygen, producing rust.

• The property tested is reactivity; the procedure checks if the sample changes when mixed with vinegar (acetic acid).

• The property tested is density; the procedure measures the mass and volume of the sample.

Answer explanation

The correct choice is that the property tested is density, as the procedure involves measuring the mass and volume of the salt block, which directly relates to its density.

Which is a chemical property of baking soda?

• A. Baking soda is soluble in water

• B. Baking soda is white

• C. Baking soda is a powder

• D. Baking soda reacts with vinegar

Answer explanation

The correct choice is D. Baking soda's reaction with vinegar produces carbon dioxide gas, which is a chemical property. The other options describe physical properties, such as solubility, color, and form.

Tags

NGSS.MS-PS1-2

Which of the following is a chemical property of the red, transparent liquid?

• red color

• transparent

• combustible

• freezing point

Answer explanation

The correct choice is 'combustible' because it describes a chemical property related to the substance's ability to burn. The other options, such as color and transparency, are physical properties.

Two gold samples must have the same

• mass.

• volume.

• length.

• density.

Answer explanation

Two gold samples must have the same density because density is an intrinsic property of a material. Gold has a specific density, so any two samples of gold will share this characteristic, regardless of their mass, volume, or length.

Which is a chemical property of water?

• Water expands when it freezes.

• Water boils at 100°C.

• Water can separate into hydrogen and oxygen.

• Water is denser than ice.

Answer explanation

The correct choice, 'Water can separate into hydrogen and oxygen,' describes a chemical property, as it involves a change in the chemical composition of water. The other options describe physical properties.

What is the difference between a physical change and a chemical change?

• A. A physical change can give off light, but a chemical change does not.

• B. A physical change is not reversible, but a chemical change is.

• C. Different substances are present after a physical change, but not after a chemical change.

• D. Different substances are present after a chemical change, but not after a physical change.

Answer explanation

A physical change alters the form of a substance but not its chemical composition, so the same substances remain. In contrast, a chemical change results in the formation of new substances, making option D the correct choice.

Tags

NGSS.MS-PS1-2

When you crack a glow stick, two substances mix and light is released. What kind of change is this? Give evidence.

• It is a chemical change because light is released, which is a sign of a chemical change.

• It is a physical change because light is released, which is a sign of a physical change.

• It is a chemical change because the shape changes, which is a sign of a physical change.

• It is a physical change because two substances mix, which is a sign of a physical change.

Answer explanation

It is a chemical change because light is released, indicating a chemical reaction has occurred. This release of energy in the form of light is a hallmark of chemical changes, distinguishing it from physical changes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is a physical change?

• A. Burning a log.

• B. Baking a cake.

• C. A penny turns green.

• D. Water pipe freezes and cracks.

Answer explanation

D is correct because when a water pipe freezes, it undergoes a physical change as it changes state from liquid to solid. The other options involve chemical changes, where new substances are formed.

When you burn a candle, which two changes occur?

• Lighting the wick is a chemical change because soot/ash forms; melting the wax is a physical change because it changes state.

• Lighting the wick is a physical change because soot/ash forms; melting the wax is a chemical change because it changes state.

• Lighting the wick is a chemical change because light is released; melting the wax is a chemical change because the wax is destroyed. There are no physical changes.

• Lighting the wick is a physical change because the wick changes size; melting the wax is a physical change because it changes state. There are no chemical changes.

Answer explanation

Lighting the wick is a chemical change as it produces soot/ash, while melting the wax is a physical change since it only changes state from solid to liquid without altering its chemical composition.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5