Question

A radioactive source emits three types of radiations.When the particle of one of these types becomes neutral, they are found to be the atoms of a rare gas. Name this rare gas.

• A. Helium
  
• B. Hydrogen
  
• C. Deuterium
  
• D. Tritium
  

Answer 1

Answer: (A)

Helium

$\begin{array}{c}\\ \text{the partical having lowest penetrating power}\\ \text{will neutralise, and also alpha particle}\\ \text{have the lowest penetrating power. so, it will}\\ \text{neutralise. and neutralise form of alpha i.e.}\\ \text{helium gases, hence the rare gas is helium}\\ \text{hence option A is correct}\end{array}$