Question

or state the following.
The three isotopes of hydrogen
Two elements having same number of protons and electrons but different number of neutrons.
The valency of an element whose electronic configuration is 2.8.3.
The shell closest to the nucleus of an atom
An element having valency'zero'​

Answer 1

Answer:

1. Protium, Deuterium and Tritium.

2. Isotope

3. +3

4. K shell

5. Noble or Inert (Usually Gases)