Question

`A1`though the elements in the periodic table are arranged according to electron structure, we make an exception for
A. neon
B. helium
C. radon
D. xenon

Answer 1

Correct Answer - B
Helium `(1s^(2))`. Rather than placing it with the other `ns^(2)` configuration elements, the alkaline earth metals, it is placed with the other noble gases (of configuration `ns^(2)nsp^(6))` because of chemical similarities).