Question

A photon has 8.0 × 10–15 J of energy. Planck’s constant is 6.63 × 10–34 J•s.

What is the frequency of the photon?

1.21 × 1019 Hz
8.3 × 10–20 Hz
1.21 × 10–19 Hz
8.3 × 1020 Hz

Answer 1

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:

\[
\boxed{1.21 \times 10^{19} \, \text{Hz}}
\]