
1. It is difficult to
a solid because there is so little
between the particles.
2. Solids are usually
materials because there are strong
between the particles.
3a. When a solid is
the particles
faster and knock into each other more energetically.
3b. This causes the particles to move apart and the solid to
to a slightly greater volume.
4a. Only
forces hold the particles of a liquid together and so they are not strong and flow
.
4b. When a coloured crystal is dropped in water, the colour slowly
and this speeds up if the water is
.
4c. This is because particles move
when heated.
5a. The particles in a gas are
spaced and so they are easily
.
5b. They also move
in all directions and hit each other and in sunlight you can see
specks dancing.