A certain crystal has an interatomic spacing of 0.442 nm. A beam of neutrons moving with a speed of 1640 m/s is diffracted from the crystal. What is the de Broglie wavelength of the neutron?
A) 0.121 nm
B) 0 nm
C) 0.241 nm
D) 0.484 nm
E) 0.682 nm

Question

Quizplus · Accepted Answer

The de Broglie wavelength of a particle is given by: 
λ = h/p
where h is Planck's constant and p is the momentum of the particle. For a neutron, the momentum is given by:
p = mv
where m is the mass of the neutron and v is its velocity.

First, we need to convert the given velocity of the neutron into momentum: 
p = mv = (1.6749 × 10^-27 kg)(1640 m/s) = 2.74996 × 10^-22 kg m/s

Then, we can use the formula for de Broglie wavelength: 
λ = h/p = (6.626 × 10^-34 J s)/(2.74996 × 10^-22 kg m/s) ≈ 0.241 nm

Therefore the answer is C, 0.241 nm.

A Certain Crystal Has an Interatomic Spacing of 0