The particulate nature of matter
1.1 The particulate nature of matter
State the distinguishing properties of solids, liquids and gases
Describe the structure of solids, liquids and gases in terms of particle separation,
arrangement and types of motion
Solids, liquids and gases have different physical properties. The difference in these
properties comes from differences in how the particles are arranged in each state.
Solids
Strong forces of attraction between particles, particles are packed very closely together in a
fixed and regular pattern
Atoms vibrate in position but can’t change position or move
Solids have a fixed volume, shape and high density
Liquids
Weaker attractive forces in liquids than in solids, particles are close together in
an irregular, unfixed
Particles can move and slide past each other which is why liquids adopt the shape of the
container they’re in and also why they are able to flow
Liquids have a fixed volume but not a fixed shape and have a moderate to high density
Gases
No intermolecular forces, particles are in random movement and so there is no defined
pattern
Particles are far apart and move quickly (around 500 m/s) in all directions, they collide with
each other and with the sides of the container (this is how pressure is created inside a can of
gas)
No fixed volume, since there is a lot of space between the particles, gases can be
compressed into a much smaller volume. Gases have low density
Describe changes of state in terms of melting, boiling, evaporation, freezing, condensation
and sublimation
, Melting
Melting is when a solid changes into a liquid
Requires heat energy which transforms into kinetic energy, allowing the particles to move
Occurs at a specific temperature known as the melting point (m.p.) which is unique to each
pure solid
Boiling
Boiling is when a liquid changes into a gas
Requires heat which causes bubbles of gas to form below the surface of a liquid (imagine a
boiling pan of water – the entire body of liquid is boiling and forming gas bubbles) allowing
for liquid particles to escape from the surface and within the liquid
Occurs at a specific temperature known as the boiling point (b.p.) which is unique to each
pure liquid
Evaporation
When a liquid changes into a gas. Evaporation occurs only at the surface of liquids where
high energy particles can escape from the liquid’s surface at low temperatures, below the
b.p. of the liquid
1.1 The particulate nature of matter
State the distinguishing properties of solids, liquids and gases
Describe the structure of solids, liquids and gases in terms of particle separation,
arrangement and types of motion
Solids, liquids and gases have different physical properties. The difference in these
properties comes from differences in how the particles are arranged in each state.
Solids
Strong forces of attraction between particles, particles are packed very closely together in a
fixed and regular pattern
Atoms vibrate in position but can’t change position or move
Solids have a fixed volume, shape and high density
Liquids
Weaker attractive forces in liquids than in solids, particles are close together in
an irregular, unfixed
Particles can move and slide past each other which is why liquids adopt the shape of the
container they’re in and also why they are able to flow
Liquids have a fixed volume but not a fixed shape and have a moderate to high density
Gases
No intermolecular forces, particles are in random movement and so there is no defined
pattern
Particles are far apart and move quickly (around 500 m/s) in all directions, they collide with
each other and with the sides of the container (this is how pressure is created inside a can of
gas)
No fixed volume, since there is a lot of space between the particles, gases can be
compressed into a much smaller volume. Gases have low density
Describe changes of state in terms of melting, boiling, evaporation, freezing, condensation
and sublimation
, Melting
Melting is when a solid changes into a liquid
Requires heat energy which transforms into kinetic energy, allowing the particles to move
Occurs at a specific temperature known as the melting point (m.p.) which is unique to each
pure solid
Boiling
Boiling is when a liquid changes into a gas
Requires heat which causes bubbles of gas to form below the surface of a liquid (imagine a
boiling pan of water – the entire body of liquid is boiling and forming gas bubbles) allowing
for liquid particles to escape from the surface and within the liquid
Occurs at a specific temperature known as the boiling point (b.p.) which is unique to each
pure liquid
Evaporation
When a liquid changes into a gas. Evaporation occurs only at the surface of liquids where
high energy particles can escape from the liquid’s surface at low temperatures, below the
b.p. of the liquid
