Question

The energy of a given wave in the electromagnetic spectrum is 2.64 × 10-21 joules, and the value of Planck’s constant is 6.6 × 10-34 joule·seconds
4.00 × 1012 hertz
2.34 × 10-12 hertz
1.30 × 1013 hertz
2.52 × 10-6 hertz
8.11 × 10-7 hertz

Answer 1

We are given
E = 2.64 × 10-21 J
h = 6.6 × 10-34 J s

The options given below are frequencies, therefore, the question must be asking about the frequency fo the given wave

The equation is
E = h f
Simply substitute and solve for f which is the frequency
f = 2.64 × 10-21 J / 6.6 × 10-34 J s
f = 4.00 × 1012 hertz