Chemistry
Study Guide – The Electron
Chapter 5 – The Electron Study Guide
I. The Atom
A. Nucleus
1. p+  gluon (strong force)  no
2. Each p+ and no has 3 quarks held together by weak force bosons
3. Neutron decays into electron (lepton) and neutrinos
a. Called Beta radiation
B. Electron Models
1. Thomson – Plum Pudding Model
2. Rutherford – Planetary Model
3. Bohr – Quantum Model
a. e- in 7 energy levels – K, L, M, N . . .
4. Schrodinger – Electron Cloud Model
II. The Electron – Quantum Mechanics
A. Electrons in atoms have discrete energies
1. These are the e- energy states or levels
2. Symbolized by “n” and rank from 1 to 7
3. e- start in their ground state
a. If absorb energy – move up to their excited state
b. When release energy – it is in form of light called
a photon with a specific wavelength and frequency
c. Can tell the two energy states by the wavelength and
frequency of photon released
4. Max Planck called these packets of released energy quanta
a. E = hν
b. h is Planck Constant = 6.626 x 10-34 Joules
B. Electron Wave Function
1. Louis de Broglie
a. λ = h/mν
b. e- have a wave and particle nature like light does
c. e- orbitsing nucleus must fit into the circumference of circle
an integral number of times: 2πr = nλ
C. Werner Heisenberg
1. Probability for e- position (x) and momentum (p)
a. (Δ p)(Δ x) = nh / 4π
D. Erwin Schrodinger
1. Electron Cloud Model
a. Quantum Numbers
(1) n = period = energy level (1 to 7)
(2) l = orbital type/sublevel = s, p, d, f
(3) ml = orientation of orbitals / angular momentum (mvr)
(4) ms = spin = +1/2 or -1/2
b. Energy level
(1) maximum e- capacity for level = 2n2
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Chemistry
Study Guide – The Electron
E.
F.
G.
H.
c. Sublevel
(1) s = sharp
(2) p = principle
(3) d = diffuse
(4) f = fundamental
(a) Sublevel (l) = n – 1
d. Spin
(1) Pauli Exclusion principle – no 2 e- in same atom can
have same quantum numbers
(a) In same orbital – must spin in opposite directions
Aufbau Principle
1. Electrons fill lowest energy levels and suborbitals first, then move upwards
2. Aufbau Diagram – e- configuration and mapping
Hund’s Rule
1. Each suborbital must receive one e- before filling up to max. of 2
Valence Level
1. Outermost shell of electrons
2. Use Roman Numerals on Groups to see how many valence electrons
a. Use Period number to know what energy level these are in
b. Know the s, p, d, and f block elements from Chart
3. Octet Rule – atoms want to fill up their valence level or rid selves of ein order to have one
Lewis Dot Diagrams
1. Valence electrons around symbol as dots
2. Long form of electron configuration and short form
III. Electromagnetic Radiation (EMR)
A. Max Planck
1. Studying heated metal – noted heat transformed into light spectrum
a. Conservation of Energy
2. E = hν where h is constant and ν is frequency (Hz or s-1)
B. Albert Einstein
1. Energy of photon
2. Epnoton = hν = hc / λ
a. c is speed of light – constant for all EMR = 3.0 x 108 m/s
C. Neils Bohr
1. Noted cetain wavelengths of light spectrum showed up when
heating/energizing H atoms
2. Determined the bands of light shown were the representation of light
wavelength and frequency that corresponded to enrgy released by e- movement
from ground to excited and back to ground states
3. Spectrometer (NASA)
D. Spectrum Series
1. Each series represents the starting (n) and final (n’) of electron
2. A measure of absorbed and emitted energy by the electrons
3. Series
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Chemistry
Study Guide – The Electron
a.
b.
c.
d.
e.
f.
Lyman Series = n > 2 to n’ = 1
Balmer Series = n > 3 to n’ = 2
Paschen Series = n > 4 to n’ = 3
Brackett
Pfund
Humphreys
III. Quantum Equations
A. c = λν
1. Deriviations
B. Ephoton = hν = hc / λ
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