Question #b3306

1 Answer
Jan 30, 2017

Helium is in period 1 Helium is part of the group or family of inert gases.


Helium has two total electrons and 2 valance electrons. These two electrons fill the 1s orbital. As the 1s orbital is the only orbital in the first period the two valance electrons completely fill the first electron shell or period.

The other members of the inert gases have eight valance electrons, which fills the respective shells of their periods. This is analogous to to the two valance electrons filling the first period shell of Helium.

It is technically incorrect to say that Helium is part of group VIIIA. As can be seen by the Roman numeral of this group the elements in this group have eight valance electrons. Helium has only two. However in terms of chemical properties and behavior Helium belongs as part of the Group VIIIA family.