One Fairly Crude Method of Determining the Size of a Molecule

Multiple Choice

One fairly crude method of determining the size of a molecule is to treat the molecule as an infinite square well (a box) with an electron trapped inside,and to measure the wavelengths of emitted photons.If the photon emitted during the n = 2 to n = 1 transition has wavelength 1940 nm,what is the width of the molecule? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,
M_el = 9.11 × 10^-31 kg)

A) 1.33 nm
B) 1.12 nm
C) 1.21 nm
D) 1.45 nm