State Gauss's law in electrostatics and provide its mathematical expression.

(N/A) Gauss's law states that the total electric flux $\Phi_E$ through any closed surface (Gaussian surface) is equal to $\frac{1}{\epsilon_0}$ times the net charge $q_{enclosed}$ enclosed by the surface.
Mathematically,it is expressed as:
$\Phi_E = \oint_S \vec{E} \cdot d\vec{A} = \frac{q_{enclosed}}{\epsilon_0}$
Where:
- $\Phi_E$ is the electric flux.
- $\oint_S$ represents the surface integral over a closed surface $S$.
- $\vec{E}$ is the electric field vector.
- $d\vec{A}$ is the area vector of an infinitesimal surface element.
- $q_{enclosed}$ is the total charge enclosed within the surface.
- $\epsilon_0$ is the permittivity of free space.