Question

What do you mean by $1\mathrm{eV}$?

Answer 1

Electron volt:

1. $1\mathrm{eV}$ is defined as the energy gained by an electron when it has been accelerated by a potential difference of $1\mathrm{volt}$, hence $1\mathrm{eV}=1.{{60210}^{-19}}_{}\mathrm{J}$.
2. $\mathrm{eV}$ stands for electron volt.

Mathematically,

$$\begin{gathered} \mathrm{W}=\mathrm{q}∆\mathrm{V} \\ =1{\mathrm{e}}^{-}\mathrm{C}\left(1\mathrm{V}\right)\frac{\mathrm{J}}{\mathrm{C}} \\ \mathrm{W}1\mathrm{eV}=1.6\times {10}^{-19}\mathrm{J} \end{gathered}$$

Here,

$\mathrm{eV}$ is the electron volt.

$\mathrm{J}$ is the joules.

$\mathrm{W}$ is the work done.

$\mathrm{q}$ is the charge.

$\mathrm{V}$ is the potential difference.

Therefore, it is the energy an electron would gain in moving between two points having a potential difference of $1\mathrm{volt}$.