The correct answer is all of the above. In a nuclear reactor, the moderator is usually made of graphite, placed between the fuel rods, and used to slow down neutrons. The nuclear moderator is a medium in which reduces the speed of the fast neutrons.
Answer:
λ = 3.1824 10-25 m
Explanation:
To release the electron from the power well the absorbed photon electro must be greater than or equal to the energy of the electron in the power well
The photon energy is E_photon = 0.625 J
The speed of light is
c = λ f
Let's use Planck's equation
E = h f
We substitute
E = h c / λ
λ = h c / E
λ = 6.63 10-34 3 108 / 0.625
λ = 3.1824 10-25 m
By definition, a region of space that contains no matter at all is a vacuum.
