Lesson 2.7 - Group 7

Halogens

The elements in Group 7 are known as the 'Halogens'.

Halogens are non-metals - some are liquid, some are gas.

They bond covalently in pairs.

Electronic structure

The halogens have 7 electrons in their outer shell.

This means they need to gain 1 electron to become stable.

This means they react with metals, particularly Group 1 metals (as they give away 1 electron).

Reactivity

Group 7 halogens react with metals to form ionic bonds. This is where they transfer electrons.

They also bond with non-metals to form covalent bonds. In these bonds, electrons are shared.

Patterns

The melting and boiling point increase going down the group.

The reactivity decreases going down the group.