Halogens exist as diatomic molecules (e.g. F2)

It shows a trend as it goes down the group where the melting point and boiling point increases.

As it goes down the group, the state of the elements change from gas to solid

The color becomes darker as it also goes down the group with fluorine being light yellow, bromine is red-brown and astatine being black.

The reactivity decreases as it goes down the group, making fluorine the most reactive and extremely dangerous.

It forms negatively charged ions through ionic bonding with an Alkali Metal in which a Halogen gains one electron from the Alkali Metal.