Question

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 Hz? Planck’s constant is
6.63 × 10–34 J • s.

2.9 × 10–18 J
2.9 × 10–34 J
2.9 × 10–48 J

Answer 1

Use E = hf.

E = (6.63 × 10^−34 J·s)(4.4 × 10^15 s^−1) = 29.172 × 10^−19 J = 2.9172 × 10^−18 J ≈ 2.9 × 10^−18 J.

So the correct choice is 2.9 × 10^−18 J.