Chemistry U2 Review

Which phrase describes the changes that take place when a gas condenses?

• loss of energy and increased freedom of particle motion

• gain of energy and increased freedom of particle motion

• loss of energy and decreased freedom of particle motion

• gain of energy and decreased freedom of particle motion

Answer explanation

When a gas condenses, it loses energy, causing particles to move closer together, resulting in decreased freedom of motion. Thus, the correct phrase is 'loss of energy and decreased freedom of particle motion'.

Tags

NGSS.MS-PS1-4

Frost forms when water vapor changes directly from a gas to ice in a process called deposition. If you were to model the water particles before and after deposition, how would they compare?

• Before deposition, the particles vibrate in place; after deposition, they slide by each other.

• Before deposition, the particles slide by each other; after deposition, they vibrate in place.

• Before deposition, the particles vibrate in place; after deposition, they move quickly in all directions.

• Before deposition, the particles move quickly in all directions; after deposition, they vibrate in place.

Answer explanation

Before deposition, water vapor particles move freely and slide past each other. After deposition, they lose energy and become fixed in place, vibrating slightly as ice. Thus, the correct choice is that particles slide before and vibrate after.

Tags

NGSS.MS-PS1-4

How does thermal energy transfer take place when water (warmer) freezes to form ice crystals in the atmosphere (cooler)?

• Energy is transferred from the air into the water.

• Energy is transferred from the water into the air.

• Energy is transferred from the water into the ground.

• Energy is transferred from warmer ice crystals to colder ones.

Answer explanation

When water freezes, it releases thermal energy. This energy is transferred from the warmer water into the cooler air, causing the water to lose heat and form ice crystals.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

After an hour in the cooler, the sodas get colder and the ice gets warmer. Which of the following explains these changes correctly?

• The coldness is leaving the ice and going into the soda.

• The heat is leaving the ice and going into the soda.

• The coldness is leaving the soda and going into the ice.

• The heat is leaving the soda and going into the ice.

Answer explanation

The correct choice is that heat is leaving the ice and going into the soda. This process causes the ice to warm up while the sodas absorb that heat, making them colder.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Particles are spaced the farthest apart in ________ and the closest together in ________. Select the answer that best completes the sentence.

• liquids; solids

• gases; liquids

• solids; gases

• gases; solids

Answer explanation

Particles are spaced the farthest apart in gases, where they move freely, and the closest together in solids, where they are tightly packed in a fixed structure. Thus, the correct completion is 'gases; solids'.

Tags

NGSS.MS-PS1-4

Why does solid water (ice) float when placed in liquid water?

• Ice is less dense than liquid water.

• Ice has less mass than the water in which it is floating.

• Ice has less volume than the water in which it is floating.

Answer explanation

Ice floats in liquid water because it is less dense than water. The molecular structure of ice creates a lattice that occupies more space, resulting in lower density compared to liquid water, allowing it to float.

Energy in the form of heat was applied to a beaker containing a certain substance. The particles of the substance began to move farther apart until they were arranged as shown by the arrow in the diagram.

What change of state occurred to the substance in the beaker?

• The substance changed from a gas to a solid.

• The substance changed from a liquid to a gas.

• The substance changed from a gas to a liquid.

• The substance changed from a liquid to a solid.

Answer explanation

The application of heat causes the particles of a liquid to gain energy and move farther apart, resulting in a change from a liquid to a gas, known as vaporization. Thus, the correct answer is that the substance changed from a liquid to a gas.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Hamdan and Vitkus are using a Venn diagram to organize the information they learned about solids, liquids, and gases. What should they write where all of the states overlap at position 7?

• Particles are spaced far apart.

• Particles are constantly moving.

• Sample does not take shape of the container.

Answer explanation

In all states of matter—solids, liquids, and gases—particles are constantly moving. This characteristic is true for all three states, making it the correct choice for the overlap in the Venn diagram.

Tags

NGSS.MS-PS1-4

Put the particles in order by the amount of spacing between each particle. Most spacing (Farthest apart) first.

• Liquid, Gas, Solid

• Solid, Liquid, Gas

• Gas, Liquid, Solid

• Solid, Gas, Liquid

Answer explanation

In gases, particles are farthest apart, allowing for high spacing. In liquids, particles are closer but still have some spacing. In solids, particles are tightly packed with minimal spacing. Thus, the order is Gas, Liquid, Solid.

Tags

NGSS.MS-PS1-4

Hoffman drew models of particles in a substance. Which model best represents the particles in a liquid?

• A

• B

• C

• D

Answer explanation

Choice B best represents particles in a liquid, as it shows them closely packed but still able to move past each other, reflecting the fluidity and moderate density characteristic of liquids.

Tags

NGSS.MS-PS1-4