the three states of matter

what are the three states of matter?

• solid

• liquid

• gas

why are solids hard to compress (squeeze)?

because the particles in a solid are packed together in a regular pattern with almost no spaces between the particles.

what shape do solids have and why?

solids have a fixed shape, meaning they cannot flow from place to place.

what can the particles in a solid do?

they can vibrate but can’t move from place to place.

why are liquids hard to compress?

because the particles are close together with not many spaces between them.

liquids take the shape of their container what does this mean about the particles?

they can flow from place to place, that is because the particles in a liquid can move.

gases are easy to compress why?

because the particles in gases are widely spaced.

gases spread out and fill the space of what and why?

of their container, because the particles in a gas move quickly and randomly.

how can you change a state of a substance?

by putting in or taking out energy.

if you heat a solid what can it change to?

it can change state to a liquid.

solid to liquid

melting

melting takes place at?

the melting point

due to particles in a liquid moving around and having more kinetic energy than the particles in a solid what does this mean?

that you have to put energy in to convert a solid into a liquid.

what is this energy needed for?

to break the forces of attraction between the particles in a solid.

what happens to the particles once the forces of attraction are broken?

the particles can now move around.

is more energy needed or less due to the stronger the forces of attraction between the particles?

the more energy we have to put in to break these forces and the higher the melting point.

liquid to solid

freezing

when does freezing take place?

when we cool a liquid back to its melting point.

when a substance freezes what happens to the forces of attraction?

the forces of attraction between the particles reform.

liquid to gas

boiling

boiling takes place at?

the boiling point

if there are strong forces of attraction between the particles the boiling point will be and why?

high, because it takes a lot of energy to break those strong forces of attraction and boil the liquid.

gas to liquid

condensing

condensing takes place at the same temperature as?

boiling

when a substance condenses what happens to the forces of attraction between the particles?

they reform

what does the simple particle model assume?

that all particles are solid spheres

the forces of attraction between the particles have a major impact on what?

the melting and boiling points of a substance.