states of matter

In which of the following situations does helium have the greatest amount of energy?

A substance has more energy as a plasma than in any other state of matter.

A substance will _____ at the same temperature.

Any substance will condense and boil at the same temperature, assuming these processes are carried out under the same conditions. This is the temperature at which the substance transitions between liquid and gas states.

In the cooling curve for any substance, the freezing point is equal to the _____ in the heating curve of the same substance under the same conditions.

Any substance will melt and freeze at the same temperature, assuming these processes are carried out under the same conditions. This is the temperature at which the substance transitions between solid and liquid states.

As a substance _____, the particles in the substance get closer together.

As particles condense, the substance turns from gas to liquid. The particles of liquids are closer together than the particles of gas.

A stick of butter is melted in a dish in the microwave. After it melts, which of the following statements describes the butter?

As the butter melts, it goes from a solid to a liquid, which takes the shape but not the volume of its container.

When a sample of dry ice (solid carbon dioxide) undergoes sublimation in a sealed bucket, what happens to its shape and volume?

As the dry ice sublimes, it goes from a solid that has a fixed shape and volume to a gas, which takes both the shape and volume of its container.

Compare the melting points of three metals: gold (1063°C), lead (328°C), and mercury (-38.9°C). Which of the following statements is true regarding intermolecular forces of these metals?

Because gold has the highest melting point, it would take more energy to melt it than to melt lead or mercury. If a substance has a relatively high melting point, it is because the forces holding the particles together are relatively strong.

What happens to the shape and volume of a sample of helium gas when it is transferred from a tank to a balloon?

Because helium is a gas, the particles are so far away from one another that the gas takes both the shape and the volume of its container.

In which state of matter are particles moving slowest

Because solid particles have less energy than particles in other states of matter, they have the most restricted movement.

Compare the melting points of three metals: gold (1063°C), lead (328°C), and mercury (-38.9°C). Which of the following statements is true regarding the states of matter of these elements at room temperature (around 23°C)?

Because their melting points are higher than room temperature, gold and lead are solid. Because its melting point is lower than room temperature, mercury is liquid.

Which of the following phase changes requires a substance to release energy?

During condensation, a gas turns to a liquid. For this to occur, high-energy particles in the gas must release some energy for the cohesive forces to bring the particles closer together.

At the end of which phase change will a substance have less energy than it did at the beginning?

During deposition, a gas turns to a soli The particles will have less energy as a solid at the end of the phase change than as a gas at the beginning.

During which of the following phase changes will a substance absorb energy?

During sublimation, a solid turns into a gas. Because solids have less energy than gases, the solid will have to absorb energy to undergo this phase change.

What states of matter are found in a sample that is in the process of freezing?

Freezing is the process of changing from a liquid to a solid. Therefore, these two states of matter will be present as that change occurs.

During which of the following phase changes will the cohesion between the particles in a substance decrease?

If the cohesion between particles decreases, then the particles must be undergoing a phase change that allows particles to move farther apart. This happens when a substance vaporizes and turns from liquid to gas.

During which of the following phase changes will the cohesion between the particles in a substance increase?

If the cohesion between particles increases, then the particles are undergoing a phase change that brings particles closer together. This happens when gas turns into liquid.

In which state of matter do the particles of iron have the lowest amount of cohesion?

The particles in a sample of gas are farther apart than in solids or liquids and therefore have the lowest amount of cohesion.

Which of the following describes a sample that is boiling?

When a substance is boiling, liquid particles gain energy and move farther apart as they turn into gas.

If a sample of water is losing energy but its temperature is not changing, what may be happening?

When a substance is freezing, the liquid particles lose enough energy to become a solid. The temperature will not change until the phase change is complete.

A student is recording the temperature of a solid substance as he heats it over a Bunsen burner and notices that the temperature stays constant at 62°C for four minutes. How can the substance be described during these four minutes?

When heating or cooling a substance, the temperature will not change while a substance is undergoing a phase change; it will only change when it is in a single state of matter before or after the phase change. The question indicates that the sample is a solid at the beginning of the experiment, and if the student is adding energy, the substance is melting.

In which of the following phases are particles of a substance generally closest together?

In a solid, particles have the least amount of energy and do not move as much as they do in other states of matter. The strong cohesive forces between the particles keep them close together.

In which state of matter does a piece of copper metal have a definite shape and volume?

In a solid, strong cohesive forces prevent the particles from moving too far from each other. Therefore, a solid cannot flow to take the shape of its container, and it cannot expand to take the volume of the container.

In which state of matter are the intermolecular forces between particles in a substance the strongest?

In solids, particles are usually closer together than in other states of matter because of the strong cohesive forces between the particles.