Question

the group in which all elements do not have same number of valence electron is......​

Answer 1

Answer:

see below

Explanation:

In zero group, helium contains two electrons in the valence shell and the other elements , that is, neon to radon contain eight electrons in the valence shell. How satisfied are you with the answer?

Answer 2

Answer:

18th group.

helium has only 2 valence electrons unlike other group 18 (noble gases) elements which have 8 valence electrons