Question

What is a cation-electron pair, and how does it form?

Short answer

Cation-electron pair is formed when a nucleus is hit with ionizing radiation.

Step-by-step solution

Cation-electron pair

Cation-electron pair general form is $M{}^{\begin{array}{l}+\\ .\end{array}}$It contains both positive charge and a free radical on an atom/molecule.

 Explanation

All radioactivity causes ionization in surrounding matter, as the emissions collide with atoms and dislodge electrons:

Atom +ionizing radiation$\to {\text{ion}}^{\text{+}}{\text{+e}}^{\text{-}}$

From each ionization event, a cation and a free electron result, and the number of such cation-electron pairs produced is directly related to the energy of the incoming ionizing radiation.

Hence When a nucleus is bombarded with ionising radiation, a cation-electron pair forms.