Quantum Mechanical Model of Atoms Flashcards

1
Q

Quantum Mechanical Model

A
  • proposes that electrons do not travel in defined orbits but rather are localized in orbitals
  • In the current quantum mechanical model it is impossible to pinpoint exactly where an electron is at any given moment in time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Orbitals

A
  • a region of space around the nucleus defined by the probability of finding an electron in that region of space
  • region of space around the nucleus that electrons are localized and move rapidly within
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Heisenberg Uncertainty Principle

A
  • It is impossible to simultaneously determine, with perfect accuracy, the momentum and the position of an electron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Quantum Numbers

A
  • n = Principal
  • l = Azimuthal
  • ml = Magnetic
  • ms = Spin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Energy State

A
  • position and energy of an electron described by its quantum numbers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Principal Quantum Number

A
  • n (first quantum number)
  • describes the average energy of a shell
    • the larger the integer value of n, the higher the energy level and radius of the electron’s shell
    • energy difference between 2 shells = [1/n2i - 1/n2f]
  • tells you the number of subshells (l)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Azimuthal (angular momentum) quantum number

A
  • l (second quantum number)
  • refers to the shape and number of subshells within a given principal energy level (shell)
    • n limits the value of l
    • s, p, d, f
  • range of possible values for l is: 0 to (n-1)
    • s → l = 0 subshell
    • p → l = 1 subshell
    • d → l = 2 subshell
    • f → l = 3 subshell
      • (ie: electron in shell n = 4 and subshell l = 2 is said to be in the 4d subshell
  • energies of the subshell increase with increasing l value (to the right and down)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Formula for maximum number of electrons within a subshell

A

4l + 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Magnetic Quantum Number

A
  • ml (third quantum number)
  • specifies the orbital within a subshell where an electron is likely to be found
  • Each orbital can hold a maximum of 2 electrons
  • values are integers between -l and +l including 0
    • ie: s subshell where l = 0 , ml = 0 → 1 orbital
    • p subshell where l = 1, ml = -1, 0, +1
    • d subshell where l = 2, ml = -2, -1, 0, +1, +2
    • f subshell where l = 3, ml = -3, -2, -1, 0, +1, +2, +3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Atomic Orbital Shapes

A
  • The shape of orbitals, like the number of orbitals, is dependent on the subshell they are found in
  • orbitals in the s subshell are spherical
  • orbitals in the p subshell are dumbbell shaped alond x, y and z axes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Spin Quantum Number

A
  • ms (fourth quantum number)
  • indicates the spin orientation of an electron (±½) of an electron in an orbital
  • Whenever 2 electrons are in the same orbital they must have opposite spins
    • often referred to as being paired
  • electrons in different orbitals with the same ms are said to have parallel spins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Subshell Energy Levels

A
  • Electrons fill from lower to higher subshells according to the Aufbau principle aka building up principal
  • Each subshell will fill completely before electrons begin to enter the next one
    • you can recall the order the subshells are filled by the n+l rule or reading the periodic table
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

n + l rule

A
  • the lower sum of the values of the firs and second quantum numbers, n+l, the lower the energy of the subshell
    • If two subshells posess the same n+l value, the subshell with the lower n value has a lower energy and will fill first
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

electron configuration

A
  • can be abbreviated by placing the noble gas that precedes the element of interest in brackets
    • ie: an element in period 4 can be abreviated by starting with [Ar]
  • uses spectroscopic notation (combining n and l values as a number and letter, respectively) to designate the location of electrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

electron configuration of ion

A
  • Anion: add electron to the end subshell until full
  • Cation: take away electron from subshell with highest n, then highest l value
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hund’s Rule

A
  • Subshells with multiple orbitals (p,d,f) fill electrons so that every orbital in a subshell gets one electron before any of them gets a second
    • Subshells may be listed either in the order in which they fill or with subshells of the same principal quantum number grouped together
17
Q

Corollary to Hund’s Rule

A
  • half filled and fully filled orbitals have lower energies and higher stability than other states
  • Chromium and other elements in it’s group, it’s more stable to move an electron in a filled lower s subshell up to a subshell to make all orbitals half filled
  • Copper and other elements in it’s group, it’s more favorable to move an electron in an s filled subshell up to a higher subshell to make the higher subshell full
18
Q

Paramagnetic materials

A
  • Have unpaired electrons that align with magnetic fields, attracting the material to a magnet
  • paramagnetic fields will cause parallel spins in unpaired electrons and therefore cause an attraction
19
Q

Diamagnetic Materials

A
  • Have all paired electrons, which cannot easil be realigned; they are repelled by magnets
20
Q

Pauli Exclusion Principle

A
  • No 2 electrons in a given atom can posess the same set of four quantum numbers.