Question

What happens to the states of matter in the halogen group?

Answer 1

At normal temperatures, the halogen elements, `X_2`, represent gases, liquids, and solids as you go down the Group.

Explanation:

Both fluorine and chlorine are diatomic gases at room temperature and pressure. Bromine is a liquid (elemental liquids are rare; can you think of another one?) Iodine is a volatile solid. Astatine is a short-lived species, which is not normally handled. As we descend the Group, van der Waals interactions between molecules became greater (as the electron cloud becomes bigger and more polarizable); hence the transition gas to (a) liquid to solid..