ch. 29

Question 1

what does light emitted by a gas discharge tube contain?

Answer 1

only discrete wavelengths

Question 2

every wavelength that is absorbed is also _______ but not every ______ is absorbed

Answer 2

every wavelength that is absorbed is also emitted but not every wavelength that is emitted is also absorbed

Question 3

what is the atomic number

Answer 3

it is the number of protons or electrons in a neutral atom

Question 4

what is Z

Answer 4

Z is the number of protons in the nucleus

Question 5

what is N

Answer 5

N is the number of neutrons

Question 6

what is A

Answer 6

it is the mass number which is the number of protons plus the number of neutrons which is in the unit of atomic unit u

Question 7

what are isotopes

Answer 7

isotopes are atoms of the same element with the same number of protons but they differ in the number of neutrons

Question 8

what are stationary states

Answer 8

they are particular arrangements of electrons in allowed orbits

Question 9

Eahc stationary state has a discrete, well-defined:

Answer 9

Energy En that is quantized

Question 10

what is a transition or quantum jump of an atom

Answer 10

it is when an electron in an atom absorbs or emits a photon when jumping to higher or lower stationary states

Question 11

what is collisional excitation

Answer 11

atoms can move from lower to higher energy states by absorbing energy in a collision with a high energy electron

Question 12

what spectra do atoms emit

Answer 12

they emit a discete spectrum where the energy of the photon emitterd or absorbed is equal to the energy difference between the two states

Question 13

what is the balmer series

Answer 13

it is consisting of transitions ending on the m=2 state, gives visible wavelengths

Question 14

what is the lyman series

Answer 14

it ends on the m=1 state and is in the utltra violet region of te spectrum

Question 15

what is the principal quantum number

Answer 15

it defines the energy of hydrogen atoms

Question 16

what is L and how does it relate to l

Answer 16

L is the angular momentum of the orbit and l is the orbital quantum number

Question 17

what is m

Answer 17

it is the magnetic quantum number and it is the tilt of the orbit

Question 18

what is ms

Answer 18

it is the spin quantum number which can point up or down

Question 19

what are the four quantum numbers

Answer 19

n, l, m, ms

Question 20

what are the values of l and the symbols

Answer 20

if l=0 it is s
if l=1 it is p
if l=2 it is d
if l = 3 it is f

Question 21

what value is l in relation to n

Answer 21

it is l ≤ n-1

Question 22

what is m in relation to l

Answer 22

-l ≤ m≤ l

Question 23

what is ms

Answer 23

it is +1/2 or -1/2

Question 24

if the subshell is s, what is the value of l,m and the number of states

Answer 24

l=0, m=0, two states possible (up or down)

Question 25

if the subshell is p, what is the value of l,m and the number of states

Answer 25

l=1, m= -1,0,1, there are 6 possible states (3m*2)

Question 26

if the subshell is d, what is the value of l,m and the number of states

Answer 26

l is 2, m is 2,1,0,-1,-2 there are 10 possible states

Question 27

if the subshell is f, what is the value of l,m and the number of states

Answer 27

l=3 m=3,2,1,0,-1,-2,-3 there are 14 states

Question 28

if a multi-electron atom, for each n what happens to l

Answer 28

for each n, the energy increases as l increases

Question 29

what is the order of orbital filling for the 3-4 levels

Answer 29

3s3p4s3d 3d is higher energy to it fills later

Question 30

what is the pauli exclusion principle

Answer 30

no two numbers can have the same set of quantum numbers

Question 31

when does collisional excitation occur

Answer 31

when the energy of the particle exceeds the energy change

Question 32

what do x-rays do to inner electrons

Answer 32

they knock them loose and cause inner shell valancy

Question 33

when an innershell electron is knocked loose by an Xray, what occurs

Answer 33

an electron from a higher shell undergoes a quantum jump and emits a photon

Question 34

what is fluorescence

Answer 34

it is when the absorption of light at a higher frequency (shorter wavelength) is then emitted as longer wavelength, lower frequnecy light

Question 35

what is a stimulated emission, what does it produce

Answer 35

it occurs when the energy of a photon is exacty equal to the energy difference between two states., this causes a photon to be emitted when the transition occurs the incident photon is not absorbed so there are now two identical incident photons