NMR spectroscopy

Question 1

what is nmr based on?

Answer 1

bsaed on the magnetic properties of particular types of nuceli when placed into an external magnetic field

Question 2

what are the 2 different types on nmr

Answer 2

magnetic resonance imaging - MRI, and NMR spectroscopy

Question 3

which uses higher frequency? mri or nmr spectroscopy??

Answer 3

nmr spectroscopy

Question 4

what is mri used for?

Answer 4

for diagnostic imaging of soft tissues (water detection)

Question 5

do all atomic nuclei have nuclear spin and magnetic moment?

Answer 5

no

Question 6

do some nuclei have magnetic properties?

Answer 6

yes, each spinning nucleus is like a mini magnet because of its magnetic moment the nucleus can interact with an externa;l magnetic field.. the nucleus can realign itself with the field or against the field, depends how they spin.

Question 7

what do magnetic momentum on the nucleus depend on

Answer 7

depends on quantam properties of the atom

Question 8

how do you know if your nucleus is magnetically active?

Answer 8

any atom with an odd number of neutrons or protons or both

Question 9

what does spin number 0 mean in terms of magnetic properties?

Answer 9

the nuclei has an even mass number and an even atomic number, and therefore the nuclei is not magnetically active and can NEVER exhibit an NMR effect

Question 10

what does the atomic mass number tell you?

Answer 10

the number of protons plus neutrons in its nucleus

Question 11

what does the atomic number tells you?

Answer 11

the number of protons in the nucleus

Question 12

what spin number do nuclei with even mass numbers but an odd atomic number have?

Answer 12

1, 2, 3

Question 13

what is the spin number for nucleus with odd atomic numbers?

Answer 13

1/2, 3/2 etc

Question 14

when is a nucleus magnetically silent?

Answer 14

when spin number is 0 aka when atomic number and atomic mass number are even

Question 15

is carbon 12 magnetically active? and why

Answer 15

no bc has even atomic number and atomic mass

Question 16

what is sensitivity usually measured against?

Answer 16

proton which has sensitivity of 1

Question 17

why do different nuclei have different resonance frequencies in the spectrum

Answer 17

bc they have different quantum properties

Question 18

what occuipies higher energy level - spins aligned with the field or spins aligned against the field?

Answer 18

spins aligned against the field

Question 19

what occuipies lower energy level - spins aligned with the field or spins aligned against the field?

Answer 19

spins aligned with the field