Question

What happens when an electron gains energy??

Answer 1

when electron gain energy they jump between energy levels as they are rotating around the nucleus. i. e. they can move second to third level if they gain energy.

Answer 2

$\underline{\large\bf{\mathfrak{Hello!}}}$

Electron Gain Enthalpy/Energy

It can be defined as the amount of energy associated with the gain of electrons by the isolated gaseous atom.
It is represented by $Δ_{eg}H$ and is measured in KJ/mol.
It provides the measure of ease an electron can be added to an atom forming a negative ion.
Depending upon the element the process of adding an electron to the atom can either be endothermic or exothermic in nature.

------------------------×----------------------------

If an electron gains energy in an atom then the electron gets excited and forms excited state of an atom.
In an atom when electron gains energy the ground state of an atom in which the atom is most stable changes it's state to exited state in which the atom is less stable than the ground state of atom.

$<h4><marquee><font color = Pink>Hope this helps...:)$