To find the frequency of the photon, we can use the formula that relates energy (E), frequency (ν), and Planck’s constant (h):
\[ E = h \cdot \nu \]
Where:
- \(E\) is the energy of the photon,
- \(h\) is Planck's constant (\(6.63 \times 10^{-34} , \text{J·s}\)),
- \(ν\) is the frequency of the photon.
We can rearrange this formula to solve for frequency:
\[ ν = \frac{E}{h} \]
Substituting the known values:
\[ ν = \frac{8.0 \times 10^{-15} , \text{J}}{6.63 \times 10^{-34} , \text{J·s}} \]
Calculating this gives:
\[ ν = \frac{8.0 \times 10^{-15}}{6.63 \times 10^{-34}} \approx 1.21 \times 10^{19} , \text{Hz} \]
Therefore, the frequency of the photon is approximately:
\[ \boxed{1.21 \times 10^{19} , \text{Hz}} \]