Atomic structure

Question 1

planck’s constant (h)

Answer 1

6.626x10e-34 J*s

Question 2

what are the four quantum numbers?

Answer 2

n, principal quantum number
l, angular momentum (azimuthal quantum number)
m(subscript)l, magnetic quantum number
m(subscript)s, spin quantum number

Question 3

quantum number n

Answer 3

principal quantum number
can be any integer (in theory)
the larger the value of n, the larger the energy level and radius of electrons in the shell

Question 4

the max. number of electrons that can occupy a shell is defined by the equation: _______

Answer 4

2n^2, where n is the principal quantum number

Question 5

the difference in energy between two shells is defined by the equation:______

Answer 5

1/n^2(initial)-1/n^2(final), where n is the principal quantum number

Question 6

quantum number l

Answer 6

angular momentum quantum number
tells shape and number of SUBSHELLS within a given principal energy level (shell)
range of values: 0 to (n-1)

Question 7

what are the spectroscopic notation values associated with each value for quantum number l?

Answer 7

l=0--> s
l=1--> p
l=2--> d
l=3--> f
*max number of e-'s in a subshell: 4l+2, where l is angular momentum q number

Question 8

quantum number m(subscript)l

Answer 8

magnetic quantum number
specifies orbital within a subshell where an electron is most likely found
possible values: between -l and +l
*if l=1, then m(sub)l can only be -1, 0, or +1
so for p: x, y, and z

Question 9

what are the shapes of the first 5 atomic orbitals?

Answer 9

1s
2s
2px
2py
2pz

Question 10

quantum number m(subscript)s

Answer 10

spin quantum number
+1/2, -1/2
electrons in same orbital must have opposite spin

Question 11

Aufbau’s principle

Answer 11

electrons fill from lower to higher energy subshells

Question 12

Explain the two ways to fill sub shells based on Aufbau’s principle

Answer 12

1) n+l rule

2) memorize the periodic table (easiest approach)

Question 13

what is the n+l rule?

Answer 13

used to determine electron sub-shell fill: the lower the sum of the first two quantum numbers (n and l) the lower the energy of the sub-shell and it fills first

Question 14

Which sub-shell fills first: 5d? or 6s?

Answer 14

6s because of the n+l rule
5d–> n=5, l=2
6s–>n=6, l=0

Question 15

Explain notation of electron config using periodic table

Answer 15

go to the noble gas that COMES BEFORE element in question and list the shells and subshells from that gas that are filled until you reach your element

Question 16

what is the electron configuration of osmium?

Answer 16

[xe]6s^24f^145d^6

Question 17

what is the electron configuration of fluorine?

Answer 17

[He]2s^2 2p^5

Question 18

what is the electron configuration of F^1-?

Answer 18

[He]2s^2 2p^6

Question 19

what is the electron configuration of F^1+?

Answer 19

[He]2s^2 2p^4

Question 20

Electron configuration of Fe3+?

Answer 20

Fe neutral= [Ar] 4s^2 3d^6

Fe 3+ = [Ar] 3d^5

Question 21

Explain how to use Aufbau’s rule in terms of the electron configuration for anions and cations:_________

Answer 21

anion: add electron to next energy shell
cation: return to the neutral atom, take an electron away from the highest “n” sub-shell. However, if the “n’s” are tied, then whichever has the highest n+l value.

Question 22

What is Hund’s rule?

Answer 22

for sub-shells with more than one orbital (p, d, and f); they fill to maximize the number of half filled orbitals with parallel spin

Question 23

What is the exception to Hund’s rule?

Answer 23

because half filled or totally filled sub-shells are more energetically stable for d and f; electrons can be removed from an s orbital to a d orbital when one electron away from 5 or 10 (in the case of d). For example, copper SHOULD be [Ar] 4s^2 3d^9 looking at table, but is actually [Ar] 4s^1 3d^10.
this can happen in d and f shells, never in p. too much energy for p to waste, not worth the stability for it.