The de-Broglie wavelength for a He atom travelling at 1000 m/s (typical speed at room temperature) is

Solution (By Examveda Team)

This question is about the de Broglie wavelength, which tells us that even particles like atoms can behave like waves!
The de Broglie wavelength (λ) is calculated using the formula: λ = h/mv
where:
h is Planck's constant (6.626 x 10^-34 Js)
m is the mass of the particle (in kg)
v is the velocity of the particle (in m/s)
First, we need the mass of a Helium (He) atom. A He atom has a mass of approximately 4 amu (atomic mass units). To use the formula, we need to convert this to kilograms. Since 1 amu ≈ 1.66 x 10^-27 kg, the mass of a He atom is roughly 4 * 1.66 x 10^-27 kg = 6.64 x 10^-27 kg.
Now, we can plug the values into the de Broglie wavelength formula:
λ = (6.626 x 10^-34 Js) / (6.64 x 10^-27 kg * 1000 m/s)
After calculating, you will get a wavelength around 99.7 x 10^-12 m.