Gallium is a metal with a remarkably low melting point of 30 ∘C30\text{ }^{\circ}\text{C}30 ∘C.
Describe how the arrangement and movement of the gallium atoms change when a sample is heated from 15 ∘C15\text{ }^{\circ}\text{C}15 ∘C to 45 ∘C45\text{ }^{\circ}\text{C}45 ∘C.