Solids and liquids are composed of particles: molecules, atoms, and ions. Both solids and liquids contain particles that stay close together. Yet there is an important
difference in the behavior of their particles. The tightly packed particles in a solid
are locked into place, so that the solid keeps a fixed volume and shape. While a
liquid has little free space between particles, there is no regular arrangement.
These particles can slide past each other easily, allowing a liquid to flow.
Which sentence introduces the contrasts between liquids and solids?
1
Solids and liquids are composed of particles: molecules, atoms, and
ions.
2
Yet there is an important difference in the behavior of their particles.
3
Both solids and liquids contain particles that stay close to one
another.