properties of solids

Question 1

what is the equation for the magnetic moment

Answer 1

u = 2rootS(S+1)

Question 2

what is the magnetic moment measured in(units)

Answer 2

Ub

Question 3

S =

Answer 3

n/2

Question 4

n =

Answer 4

number of unpaired electrons

Question 5

what is paramagnetic (no field applied)

Answer 5

random alignment

Question 6

what is ferrimagnetic (no field applied)

Answer 6

big up, small down

Question 7

what is antiferromagnetic (no field applied)

Answer 7

big up, big down

Question 8

what is ferromagnetic (no field applied)

Answer 8

all big up

Question 9

at high temperatures different magnetic alignments …

Answer 9

act very similar

Question 10

what is the equation for the molar heat capacity

Answer 10

C = Q/n.deltaT

Question 11

what is the S.I unit for Q

Answer 11

J

Question 12

what is the S.I unit for C

Answer 12

J K-1 Mol-1

Question 13

what is a semi conductor

Answer 13

a material which has been intensionally doped with impurities to alter its electrical conductivity

Question 14

intrinsic vs extrinsic

Answer 14

intrinsic is undoped semiconductors whereas extrinsic is a doped semiconductor

Question 15

draw the plot of extrinsic vs intrinsic

Question 16

what is the equation for calculating reflectivity

Answer 16

(n2-n1/n2+n1)^2

Question 17

E = ____ =______=_____

Answer 17

hv = hc/lambda = hcw where w is the wavenumber in m-1

Question 18

red light has the ____ wavelength

Answer 18

highest

Question 19

n (refractive index) =

Answer 19

c (velocity of light in vacuum) / v (velocity of light in medium)

Question 20

reflected light is the same ______ as incident

Answer 20

frequency

Question 21

doped with an ion with more valence electrons =

Answer 21

donor level is formed (extra valence)

Question 22

doped with an ion with less valence electrons =

Answer 22

hole level is formed (electrons can be absorbed by this which is in the conduction band)

Question 23

what is the Eg

Answer 23

the energy gap between the valance and conduction band

Question 24

what if hv > Eg

Answer 24

full absorption - colour is black

Question 25

what if hv < Eg

Answer 25

no absorption - colourless

Question 26

what is Eg is in between

Answer 26

partial absorption - we get colour

Question 27

wavelength =

Answer 27

hc/Eg

Question 28

what does the sigma mean

Answer 28

the electrical conductivity at temperature T

Question 29

what is the units of sigma

Answer 29

Sm-1(siemens )

Question 30

what does the sigma 0 mean

Answer 30

the maximum conductivity

Question 31

what is the currie- Weiss equation

Answer 31

Xm = c / T - 0(theta)

Question 32

theta = 0 , it is

Answer 32

paramagnetic

Question 33

theta < 0,

Answer 33

antiferromagnetic

Question 34

theta > 0,

Answer 34

ferromagnetic

Question 35

what happens at the curie temp

Answer 35

the magnetic susepatability increases dramatically

Question 36

what happens at the neel temp

Answer 36

susceptibility begins decreasing