Convert the given energy from electron volts (eV) to Joules (J).

The energy ($E$) is $3.3 \text{ eV}$.
We know that $1 \text{ eV} = 1.602 \times 10^{-19} \text{ J}$.

$$E = 3.3 \text{ eV} \times (1.602 \times 10^{-19} \text{ J/eV})$$ $$E = 5.2866 \times 10^{-19} \text{ J}$$

The equation is $E = hf$, where $h$ is Planck's constant ($6.626 \times 10^{-34} \text{ J}\cdot\text{s}$).
Rearrange the formula to solve for $f$:

$$f = \frac{E}{h}$$ $$f = \frac{5.2866 \times 10^{-19} \text{ J}}{6.626 \times 10^{-34} \text{ J}\cdot\text{s}}$$ $$f \approx 0.797857 \times 10^{15} \text{ Hz}$$ $$f \approx 7.97857 \times 10^{14} \text{ Hz}$$

Rounding to three significant figures:

$$f \approx 7.98 \times 10^{14} \text{ Hz}$$

The frequency of the photon is:

$$7.98 \times 10^{14} \text{ Hz}$$