1A Atomic Structure Flashcards
Berzelius In vs Org
Vitalism: life/organs needed to make organics
Who proved vitalism wrong
Wohler
Who made atom theory
Dalton
An atom consists of
One nucleus surrounded by an electron cloud
What determines the size/radius of an atom
Electron cloud
Role of the nucleus
Accommodate nucleons and determine weight
Electron mass in Coulumbs
1.602e-19 C
Mass of proton
1.673e-27 kg
Mass number
Protons + neutrons
Atomic number
Number of protons
What is an isotope
Nuclei with equal Z (atomic numbers)
What is an isobar
Nuclei with equal mass numbers (A)
What is an isotone
Nuclei with equal A - Z (mass - atomic)
What happens if there is high binding energy between nucleons
Significant mass defect
What is an electron to the Bohr model
Particles
What is an electron to the orbital models
Waves
Maximum occupancy in a shell for Bohr
2n^2 where n = 1 (K), 2 (L) etc
Bohr: Energy of electron depends on
Shell
Lyman series range
122 nm to 94 nm
Balmer series range
656 nm to 410 nm
Paschen series range
1875 nm to 1094 nm
Bohr: n is the…
She’ll number
What does the electron do in bohr
Circles in shells (orbits) around nucleus
Bohr: Can electrons exist between shells
Nope because they have discrete energy values
Bohr: Is it harder to remove an electron from K or L
4x harder to remove from K
Bohr: n can be interpreted as
Principal quantum number
Problems with the Bohr model
- Violates classic theories of electromagnetism
- Violates Heisenberg uncertainty principle
- Predictions for multi-e species wrong
- Struggles to explain relative emission intensities
- Fail to explain fine structure in spectral lines
Bohr: what happens to elements other than H
Splitting of lines in emission spectrum (fine structure)
Describe fine structure of alkali metal emission lines
Space, Principal, Diffuse, or Fundamental
De broglie said about electrons…
Each moving particle possess a wave character
Schrödinger came up with the
Wave function of a quantum mechanical system
Probability of density of finding a system in a given state when measured is proportional to
square of amplitude of the systems wave function at that state
Principal quantum number
N = 1, 2, 3…
Azimuthal quantum number
L = 0, … n- 1
Magnetic quantum number
Ml = -l, …, + l
Radial nodes in ns orbital
N - 1
Radial nodes in np orbital
N - 2
Radial nodes in nd orbitals
N - 3
Radial nodes in nf orbitals
N - 4
Abbreviation for angular nodes / nodal planes
l (that’s a lowercase L)
No nodal plane
S orbital, l = 0
One nodal plane
P orbital, l = 1
Two nodal planes
D orbital, l = 2
Three nodal planes
F orbital, l = 3
Orbital: n =
Main energy level (aka shell)
Orbital: azithmul l =
Subshell, shape
Orbital: m =
Orbital orientation (2px etc)
azithmul l values for each orbital
S is 0, P is 1, d is 2, f is 3
Energy of every system is determined by
Net interaction
Only attractive interaction btwn hydrogenic systems vs many e systems
Electron to nucleus: electrostatic attraction
Electrostatic attraction
Electron to nucleus
Electrostatic repulsion
Electron to electron
Spin coupling
Two electrons in same orbital
Is spin coupling attractive or repulsive
Attractive
What’s wrong with the Schrödinger equation
Too complex for many electron systems so the only approximations are for non hydrogenic species
Aufbau principle
Predict lowest energetic state (ground) of multi e systems
Pauli exclusion principle
Two or more electrons cannot occupy same quantum state
What is the point of magnetic spin quantum number
Differentiate between two electrons in the same orbital
Ms =
-1/2, +1/2
Madelung-Klechkovsky Rules
- Lowest n+l first
- For equal n+l, lowest n first
- Works only for atoms, not ions
If n > 1
Multiple l values for the same shell; sub shells
If l > 0
Multiple ml values for the same subshell, causing different orientations
Degenerate subshell means the ml states are
Energetically equal
Hunds rule
Every orbital in a sublevel is singly occupied before any orbital is doubly occupied
Effects of hunds rule
Minimize spin coupling per subshell. Every degenerate ml must be filled with one electron before adding a second to any single occupied ml
Slaters rule
- Inner electrons (lower n or lower) partially shield the attractive force of the nucleus from outer electrons (higher n or l)
- The effective nuclear charge Zeff experienced by outer electrons is lower than the absolute nuclear charge Z
- The semi empirical values for the shielding constant s are derived from electron excitation and ionization experiments
Slaters rule equation
Zeff = Z - s
Slaters rules for electrons in ns or np
- Each other ns or np electron shields 0.35 except for 1s which contribute 0.30
- Each electron in penultimate (n-1) shell shields. 0.85
- Each electron in lower shells shields 1
Slaters rules for nd or nf
- Each other nd or nf electron shields 0.35
- Each electron in lower subshells shields
azithmal number for s
0
azithmal for p
1
azithmal for d
2
azithmal for f
3
angular nodes =
azithmal number l
radial nodes in 4f
0
angular nodes in 5d
2
mass of an electron
9.109e-31 kg
speed of light
3e8 m/s
planck’s constant
6.626 e-34 Js
R in J/molK
8.314
R in Latm/molK
0.08206
Joules can also be written as
kgm2 / s2
kilo
10^3
deci
10^-1
centi
10^-2
milli
10^-3
micro
10^-6
nano
10^-9
pico
10^-12
