Â€˘ in which of the group 18 elements, 8 electrons in the outermos

1.	Â€˘ in which of the group 18 elements, 8 electrons in the outermost shell is not present
Answer» Helium. Reason: it has atomic number 2 and so has 2 ELECTRONS in its FIRST and only shell. It is placed in GROUP 18 as it has closed shell i.e. completely FILLED valence shell configuration.

Â€˘ in which of the group 18 elements, 8 electrons in the outermost shell is not present

Answer»

Helium.

Reason: it has atomic number 2 and so has 2 ELECTRONS in its FIRST and only shell.

It is placed in GROUP 18 as it has closed shell i.e. completely FILLED valence shell configuration.