Calculate the Wavelength, in Nanometers, of Light Emitted by a Hydrogen

Calculate the wavelength, in nanometers, of light emitted by a hydrogen atom when the electron falls from an n = 7 energy level to an n = 4 energy level. Recall that the quantized energies of the levels in the hydrogen atom are given by:

A) 4.45 × 10^-20 nm
B) 8.51 × 10² nm
C) 2.17 × 10³ nm
D) 1.38 × 10¹⁴ nm
E) 2.16 × 10³ nm