UNIT TEST 1: MATTER

Which statement best explains why air is considered matter?

• Air can be seen and touched easily.

• Air is made of atoms and molecules that have mass and take up space.

• Air only exists when it is moving.

• Air does not take up space but has energy.

A substance has no definite shape or volume, and its particles are far apart and moving rapidly.
Which state of matter best describes this substance?

• Solid

• Liquid

• Gas

• Plasma

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Two samples are tested in a lab:

• Sample A has the same chemical composition throughout and always melts at the same temperature.

• Sample B varies slightly in composition and melts over a range of temperatures.
  Based on this information, which conclusion is most accurate?

• Both samples are pure substances because they contain matter

• Sample A is a pure substance, and Sample B is not

• Sample B is a pure substance because it melts over a range

• Neither sample is a pure substance because both can melt

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A scientist analyzes two unknown samples:

• Sample X contains only one type of atom and cannot be broken down into simpler substances by chemical means.

• Sample Y contains two different types of atoms chemically bonded together.

• Which statement correctly identifies the samples?

• Both Sample X and Sample Y are elements

• Sample X is an element, and Sample Y is a compound

• Sample Y is an element because it contains atoms

• Sample X is a compound because it cannot be broken down

Tags

NGSS.MS-PS1-1

A student examines an unknown sample and records the following observations:

• The sample contains two different substances.

• Each substance keeps its original properties.

• The substances can be separated using a physical process.

Which conclusion is most accurate?

• The sample is a compound because it contains more than one substance.

• The sample is a mixture because the substances are physically combined.

• The sample is an element because it cannot be chemically separated.

• The sample is a pure substance because it has consistent properties.

Two mixtures are placed in identical containers and left undisturbed for 24 hours:

• Mixture A remains evenly cloudy, and no particles settle to the bottom.

• Mixture B initially appears mixed, but solid particles collect at the bottom over time.

Which statement best explains the difference between the two mixtures?

• Mixture A is a solution, and Mixture B is a pure substance

• Mixture A is a colloid, and Mixture B is a suspension

• Mixture A is a suspension, and Mixture B is a colloid

• Mixture A and Mixture B are both solutions because they were mixed evenly

A container of liquid water is placed in a freezer. Over time, the water turns into solid ice.

Which explanation best describes why freezing (solidification) occurs?

• Water molecules stop moving completely when they freeze

• Water molecules become chemically bonded into a new substance

• Heat is added to the water, causing molecules to spread farther apart

• Water molecules lose energy, move more slowly, and are held closer together by stronger attractions

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Water vapor in the air forms droplets on the outside of a cold glass.

Which explanation best describes why condensation occurs?

• Gas particles gain energy and spread farther apart

• New chemical bonds form, creating a different substance

• Gas particles lose energy, slow down, and move closer together to form a liquid

• Liquid particles break apart into gas particles

Tags

NGSS.MS-PS1-4

A fire extinguisher releases carbon dioxide gas, and white solid carbon dioxide (“dry ice”) forms directly from the gas.

Which explanation best describes why deposition occurs in this situation?

• The gas gains energy and changes into a liquid before freezing.

• The gas reacts chemically with oxygen to form a solid.

• The solid forms because the gas particles spread farther apart.

• The gas loses energy so quickly that its particles slow down and lock into a solid without becoming liquid.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

It is a physical quantity wherein the value is independent of the amount of substance where it is measured. 

• Intensive Property

• Extensive Property

• Chemical Change

• Physical Change