What are the characteristics of group 8A?

Answer 1

Group VII elements are halogens.

Halogens exist as diatomic covalent molecules (the 2 atoms within each molecule are held together by strong covalent bond) and they are very reactive non-metals.

Physical properties:

On going down the group from Fluorine to Astatine,

- the melting and boiling points of the halogens increase. Chlorine is a gas, bromine is a liquid and iodine is a solid at room temperature.

- the colour of the halogens become darker. Chlorine is greenish-yellow, bromine is reddish-brown and iodine is purplish-black.

Chemical properties:

- Halogens react with most metals to form salts called halides.

- The reactivity of halogens decreases down the group. Fluorine is the most reactive. This is because the atomic size of the halogens increases down the group. It becomes more difficult for the nucleus to attract an electron into the valence shell to become an ion.

- A more reactive halogen will displace a less reactive halogen from an aqueous solution.

Answer 2

halogens