Chapter 8

Question 1

What is n

Answer 1

Principle quantum number

Question 2

What is l + formula

Answer 2

Angular momentum
N-1

Question 3

What is m + formula

Answer 3

Angular momentum projection
-l to l

Question 4

What is s

Answer 4

Spin
Bosons = 1
Fermions = 1/2 (electrons = 1/2)

Question 5

What is spin projection

Answer 5

m_s
+1/2 and -1/2 usually

Question 6

Magnitude of angular momentum

Answer 6

L = sqrt(l(l+1))*(h-bar)

Question 7

Z component of magnitude of angular momentum

Answer 7

Lz = m(h-bar) = L*cos(θ)

Question 8

Atomic orbit definition

Answer 8

An area where the likelihood of finding an electron is 90%

Question 9

When are atomic orbitals circular

Answer 9

When angular momentum (l) is zero

Question 10

Orbital magnetic dipole moment definition

Answer 10

Strength of the magnetic field produced by an electron orbiting a nucleus

Question 11

What is μb

Answer 11

Bohr magneton, fundamental constant in magnetism

Question 12

Potential energy of interaction between orbital magnetic dipole moment and external magnetic field

Answer 12

U(θ) = -μz*B = mμB

Question 13

What is the Zeeman effect

Answer 13

Splitting of orbitals due to the interaction of the magnetic dipole moment and an external magnetic field (related to U = μmB)
Example of this is spots on the sun

Question 14

Formula for spin magnitude

Answer 14

S = sqrt(s(s+1))*(h-bar)

Question 15

Allowed number for spin projection (m_s)
For an electron

Answer 15

-s to s (just like for m)
For electron it’s always -1/2 and 1/2

Question 16

What is spin-orbit interaction

Answer 16

When the spin of an electron interacts with its angular momentum and produces a fine structure.
When the spin and angular momentum are aligned (same direction), it’s produces a higher energy state and a lower energy state when they are not aligned.

Question 17

What does their Stern-Geralch experiment show

Answer 17

Showed that electrons have a spin and the spin projection number with one being -1/2 and the other 1/2. This was shows as a beam of electrons from silver (which has 1 valence electron) was split into two beans under an irregular magnetic field.

Question 18

Number of possible spin projection

Answer 18

2s+1 = no. spins
Eg and electron is 1/2 so 2(1/2)+1 = 2 (these are -1/2 and 1/2)

Question 19

What is spin-spin coupling

Answer 19

When the magnetic moment of a proton (in nucleus) and electron interact causing a hyperfine structure.

Question 20

What is the 21cm line in hydrogen

Answer 20

When radiation is emitted from the transition of aligned and non-aligned spin-spin interactions in hydrogen. This results in the emission of radiation with λ = 21cm. Also show that hydrogen is present.

Question 21

What is the Pauli exclusion principle

Answer 21

No two electrons can have the same values for all quantum numbers (except spin)

Question 22

What is the formula for the allowed number of electrons in a sub shell

Answer 22

N = 4l + 2

Question 23

Number of angular orbital states in a sub-shell

Answer 23

2l+1

Question 24

Number of electrons that fill atom

Answer 24

2n^2

Question 25

What is the aufbach principle

Answer 25

Principle where each orbit must be filled before going to the next (follow the arrows) Eg 4s is filled before 3d

Question 26

What are selection rules

Answer 26

Rules that classify a transition as allowed or forbidden (forbidden still occur but low chance) Δl = +-1

Question 27

What is breaking radiation

Answer 27

When an electron is slowed down by a medium and emits x-rays

Question 28

What do each letters correspond to

Answer 28

K: n=1 L: n=2 M: n=3 N: n=4 Remember KLM (Dutch airways)

Question 29

What is Moseley’s law

Answer 29

(Z-1) = constant * sqrt(f) Or (Z-1)^2 = constant * f

Question 30

Difference in energy between orbitals for an element with atomic number Z

Answer 30

En = -13.6*((Z-1)^2)*(1/n^2-1/m^2)

Question 31

How does a laser work

Answer 31

Pump, population inversion, random emission, stimulated emission, reflection

Question 32

How does a cd work

Answer 32

Coherent light is either reflected (1) by a peak in the material or not reflected (0) allowing for information storage

Question 33

Why is blu-ray called so

Answer 33

The peaks and throughs on the disc are much smaller and require blue light to read, hence blu ray.