2.12 - States of Matter

Gases The particles of gases are not held together and can be easily compressed and expanded with heating. Gases are also free flowing and assume the shape of their container.

.They take the shape and volume of their container.

Yes, at a temperature called absolute zero, the vibrating motion of the particles stop. This occurs at -459ºF. The temperature cannot go lower than this.

Can particles of a solid ever stop moving?

The distance between particles determines the state of matter for a material. When a material changes state, the average spacing of its particles changes.

Describe how atoms and the arrangement of atoms contribute to the properties and states of matter.

Solid particles vibrate in place, and this requires energy.

Do solid particles have energy? Why or why not?

No, the chemical identity of the substance is the same. The substance is merely in a different state.

Does the identity of a substance change when it melts?

Molecules of a solid are in fixed positions, but they vibrate; whereas, molecules of a liquid can glide over one another, changing positions. But gases have no fixed volume or shape. Gas molecules have a lot more energy of motion than the molecules in a solid or liquid.

Explain how molecular motion differs in solids, liquids, and gases.

matter with no definite shape, but that takes the shape of its container and fills it completely; usually invisible

Gas

In a freezer, the air molecules absorb energy from the water, causing the water molecules to freeze into a solid.

How do ice cubes form in the freezer?

Molecules of a solid are in fixed positions, but they vibrate; whereas, molecules of a liquid can glide over one another, changing positions.

How does molecule movement in solids and liquids compare?

Solids, liquids, and gases are the three common physical states of matter. A solid is a substance with fixed volume and shape. A liquid is a substance that has fixed volume but takes the shape of any container. A gas does not have a fixed shape or volume.Vv

Identify different states of matter.

Gases have the most energy because they move around the most. The energy has been used to break the forces holding the particles near one another.

In which state of matter do the particles have the most energy? Why?

Something that flows freely and takes the shape of its container. We know water is a liquid because we can pour it, and it takes the shape of whatever container we put it in.

Liquid

Solid

Molecules are in fixed positions but vibrate in place.

Gas

Molecules are very far apart from one another. This state does not have a fixed volume.

Liquid

Molecules can glide freely over one another but are in close contact. This state does not have a fixed shape but has a fixed volume.

something with a definite shape that is not easily changedVv

Solid

Gases The particles of gases are not held together and can be easily compressed and expanded with heating. Gases are also free flowing and assume the shape of their container.

The particles do not interact with each other much.

Liquids The particles of liquids, while tightly packed, are able to move freely and assume the shape of their container.

The particles flow past one another.

Solids The particles of solids vibrate and are held in place because they are tightly held together. As a result, solids have a fixed shape.

The particles vibrate in place.

Gases The particles of gases are not held together and can be easily compressed and expanded with heating. Gases are also free flowing and assume the shape of their container.

There is a lot of free space between particles, allowing them to flow.

Solids The particles of solids vibrate and are held in place because they are tightly held together. As a result, solids have a fixed shape.

They have definite shape

Liquids The particles of liquids, while tightly packed, are able to move freely and assume the shape of their container.

They take the shape of their container but have a constant volume.

Liquids The particles of liquids, while tightly packed, are able to move freely and assume the shape of their container.

When the particles get enough energy, the substance boils.

Solids The particles of solids vibrate and are held in place because they are tightly held together. As a result, solids have a fixed shape.

When the particles get enough energy, the substance melts.

It is water vapor. When water boils, it is changing state from a liquid to a gas.

When water boils, is it steam or water vapor?

Particles in liquids and gases have enough energy to break the forces that hold them in a specific place. The particles are able to move past one another, creating the ability to flow.

Why do both liquids and gases have the ability to flow?

Solid to liquid

phase conversion when molecules gain energy to break attractive forces, allowing molecules to glide over one another Consider the result of gaining energy by the molecules.

Gas to Liquid

phase conversion when molecules lose energy, making molecules come closer together Consider the result of losing energy by the molecules.