Consider N non-interacting diatomic molecules stuck on a metal surface. Each molecule can either lie flat on the surface, in whi
ch case it must be aligned to one of two directions, x and y, or it can stand up along the z direction. There is an energy cost e > 0 associated with a molecule standing up, and zero energy for molecules lying flat along x or y directions.
What are the possible energy levels for this system of N particles, and what is the number of microstates associated to each energy level?
Find the entropy and energy of the system as a function of the temperature, T.
What is the probability of a specific molecule standing up?
What is the largest possible value of the energy of the system at any temperature?
What are the possible energy levels for this system of N particles, and what is the number of microstates associated to each energy level?
Find the entropy and energy of the system as a function of the temperature, T.
What is the probability of a specific molecule standing up?
What is the largest possible value of the energy of the system at any temperature?
1 answer:
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Since energy cannot be created nor destroyed, the change in energy of the electron must be equal to the energy of the emitted photon.
The energy of the emitted photon is given by:
where
h is the Planck constant
f is the photon frequency
Substituting
, we find
This is the energy given to the emitted photon; it means this is also equal to the energy lost by the electron in the transition, so the variation of energy of the electron will have a negative sign (because the electron is losing energy by decaying from an excited state, with higher energy, to the ground state, with lower energy)
The energy of the emitted photon is given by:
where
h is the Planck constant
f is the photon frequency
Substituting
This is the energy given to the emitted photon; it means this is also equal to the energy lost by the electron in the transition, so the variation of energy of the electron will have a negative sign (because the electron is losing energy by decaying from an excited state, with higher energy, to the ground state, with lower energy)
Answer:
Second order line appears at 43.33° Bragg angle.
Explanation:
When there is a scattering of x- rays from the crystal lattice and interference occurs, this is known as Bragg's law.
The Bragg's diffraction equation is :
.....(1)
Here n is order of constructive interference, λ is wavelength of x-ray beam, d is the inter spacing distance of lattice and θ is the Bragg's angle or scattering angle.
Given :
Wavelength, λ = 1.4 x 10⁻¹⁰ m
Bragg's angle, θ = 20°
Order of constructive interference, n =1
Substitute these value in equation (1).
d = 2.04 x 10⁻¹⁰ m
For second order constructive interference, let the Bragg's angle be θ₁.
Substitute 2 for n, 2.04 x 10⁻¹⁰ m for d and 1.4 x 10⁻¹⁰ m for λ in equation (1).
<em>θ₁ </em>= 43.33°