Is electric flux a scalar or a vector quantity?

$A$ point charge $q$ is placed at a distance $\frac{a}{2}$ directly above the centre of a square of side $a$. The electric flux through the square is

$A$ point source of $3000 \ lumen$ is located at the centre of a cube of side length $2 \ m$. The flux through one side is......$lumen$.

Two concentric spherical surfaces $P_1$ and $P_2$ enclose charges $\frac{Q}{2}$ and $4Q$ as shown in the figure. If $\phi_1$ and $\phi_2$ are the electric fluxes linked with the surfaces $P_1$ and $P_2$ respectively,then:

$A$ point charge causes an electric flux of $-2 \times 10^4 \ Nm^2 C^{-1}$ to pass through a spherical Gaussian surface of $8.0 \ cm$ radius,centred on the charge. The value of the point charge is: (Given $\epsilon_0 = 8.85 \times 10^{-12} \ C^2 N^{-1} m^{-2}$)

$A$ sphere of radius $R$ has a charge $Q$. $A$ concentric spherical Gaussian surface of radius $2R$ is drawn. The electric flux associated with the Gaussian surface is ........