The family of noble gases is called as zero group.

1. Zero group or group 18 is a family of inert gases also called as noble gases or rare gases.

2. In their atoms, all the electronic shells including the outermost shell are completely filled. They have stable electronic configuration with complete duplet (Helium) or complete octet (Neon, Argon etc).

3. So, atoms do not gain, lose or share electrons and hence have zero valency.

4. Hence, the family of noble gases is called as zero group.