Concept:
According to Gauss's Law, the total electric flux through a closed surface is given by:
\[
\Phi_{\text{total}} = \frac{q}{\epsilon_0}
\]
If a charge is placed at the center of a cube, the flux distributes equally among its six identical faces.
Step 1: Write the total flux through the cube.
\[
\Phi_{\text{total}} = \frac{q}{\epsilon_0}
\]
Step 2: Divide the flux equally among the six faces.
\[
\Phi_{\text{one face}} = \frac{1}{6} \times \frac{q}{\epsilon_0}
\]
\[
\Phi_{\text{one face}} = \frac{q}{6\epsilon_0}
\]
Thus, the electric flux through one face is:
\[
\boxed{\frac{q}{6\epsilon_0}}
\]