Quantum Theory and the Electronic Structure of Atoms

Question 1

Electrons

How Light Energy is Determined?

Answer 1

• wavelength
• frequency
• energy

Question 2

Electrons

When are wavelengths seen?

Answer 2

When electrons return to ground level

Question 3

Electrons

Planck’s Constant

Answer 3

• h
• 6.022E-34 Jᐧs
• Slope of E∝V

Question 4

Properties of Light

What is Electromagnetic Radiation

Answer 4

• EMR
• Properties of Light

Question 5

Properties of Light

Wavelength

Answer 5

• Length of one wave
• Meters
• 𝝀

Question 6

Properties of Light

Frequency

Answer 6

• Number of wavelengths(or cycles) per sec passing a point
• 1/s or s^-1 or Hz
• 𝛎

Question 7

Properties of Light

Speed of Light

Answer 7

• 2.998E8 m/s
• c

Question 8

Properties of light

Amplitude

Answer 8

• Higher is Brighter while Lower is darker

Question 9

Properties of Light

Equations for Energy, and Light Parts

Answer 9

• c = 𝝀 ᐧ 𝛎
• E = h𝛎
• E = hᐧc/𝝀
  * Is the Energy of 1 photon

Question 10

What are Photons?

Answer 10

Particle side of electrons

Question 11

Planck’s Work

What does delocalized mean?

Answer 11

the electron is not with a certain atom or nucleus

Question 12

Planck’s Work

What is a Quantum

Answer 12

A packet of Energy for an electron to jump to the next electron level

Question 13

Einstein’s work

What is Photon Energy related to?

Answer 13

• Ephoton ∝ 𝛎
• Ephoton ∝ 1/𝝀

Question 14

PES equation

Answer 14

Ephoton = KEelectron + BEelectron
- BE = binding energy

Question 15

Bohr’s Work

Energy Equation to move electron in Hydrogen

NOT IMPORTANT FOR TEST

Answer 15

ΔE = (-2.178E-18 J )((1/nf^2) - (1/ni^2))

Question 16

de Broglie’s Work

Mass Equation

Answer 16

h/(𝝀v)

Question 17

Quantum Numbers

Types

Answer 17

• n = Priniciple quantum number
• l = Angular quantum number
• m = Magnetic quantum number
• ms = Magnetic Spin

Question 18

Quantum Numbers

Nodes

Answer 18

No possibility for electron(white shell)

Question 19

Quantum Numbers

Principle Quantum Number

Answer 19

• n
• Integral Number
• Related to size and energy of orbital
• Corresponds to Bohr’s energy level
• More n
  1. Increased Orbital
  2. Increased distance of electron from orbital
  3. Increased Energy
  4. Decreased energy between orbitals

Question 20

Quantum Numbers

Angular Momentum Quantum Number

Answer 20

• Shape
• l = 0–> (n-1) for each n val
• if n=3, possible orbitals s(0)–>d(2)

Question 21

Quantum Numbers

Magnetic Quantum Number

Answer 21

• m
• integers specifying orbital orinetation
• Values are from -l←→+ l
• Includes 0
• Example: l = 2: m=-2,-1,0,1,2 ⇒ 5 orbitals

Question 22

Quantum Numbers

Electron Spin

Answer 22

• Up = + .5 spin
• Down = - .5 spin

Question 23

Quantum Numbers

Difference between H and Multielectron atoms

Answer 23

• H = subshell E levels that are degenerate(same n-int at same level)
• Multi = lower orbital energies
  * Subshell of prinicple shell at different energies

Question 24

Quantum Numbers

Rules for Electron Placement

Answer 24

1. Pauli Exclusion Principle
   * No 2 electrons in atom has same 4 quantum numbers
   * electrons in 1/2 filled orbitals have parallel spins
2. Hund’s Rule
   * One electron for each orbital before doubling up
3. Aufbau Principle
   * Electron occupy lowest energy level possible

Question 25

# Electron Configuration How do you write Electron Configuration

Answer 25

* Removal Order * Ex) Se: [Ar] 3d^10 4s^2 4p^4

Question 26

# Electron Configuration Valence Electrons

Answer 26

* Outermost principle shell * Usually S or S and P

Question 27

# Electron Configuration Shortcut using Noble Gases

Answer 27

* Can use closest previous noble gas in brackets then build the rest of the electron config from there * Cannot use this for noble gas in ground state

Question 28

# Electron Configurations Electron Configuration Exceptions

Answer 28

* Cr: [Ar] 3d^5 4s^1 (Same with Mo) * Cu: [Ar]3d^10 4s^1(Same rule with Au and Ag)

Question 29

# Ionization Energy What is Ionization Energy

Answer 29

* Minimum Energy neede to remove electron from atom or ion

Question 30

# Ionization Energy Ionization Energy Requirements

Answer 30

1. Gas State 2. Endothermic 3. Valence electron first 4. Successive removed for 2nd etc IEs

Question 31

# PES Why are X-rays used?

Answer 31

* Can dislodge electrons

Question 32

# PES Relation between BE and KE

Answer 32

* Inversely Related

Question 33

# Magnetic Properties of electrons Paramagnetic

Answer 33

* one or more unpaired electron * attracted by a magnetic field

Question 34

# Magnetic Properties of electrons Diamagnetic

Answer 34

* Paired electrons * opposite spins that cancel out their magnetic fields * Are not attracted to outside magnetic field

Question 35

# Magnetic Properties of electrons How are they detected

Answer 35

* weighing a substance in the presence of a magnetic field

Question 36

# Periodic Trends Atomic Radius

Answer 36

* Is the distance form the nucleus to the valence electrons * Across Period: decreased radius due to higher effective nuclear charge * Down Group: Increased radius due to higher n and a greater distance from the nucleus(higher n ==> higher V)

Question 37

# Periodic Trends Cations

Answer 37

* Decreased sized compared to original * decreased electrons with same proton number

Question 38

# Periodic Trends Anions

Answer 38

* Increased size * Increased electrons with same proton number * Electron - Electron Repulsion

Question 39

# Ionization Energy What is the first IE equal to?

Answer 39

* Binding Energy

Question 40

# Electron Affinity Electron Affinity

Answer 40

* Energy released when neutral atoms gain electrons 1. Needs to be in gas state 2. M(g) + 1 electron --> M^1-(g) + EA etc(Successive) * Exothermic * Increased energy leads to Increased negative EA * Outer electrons are delocalized: can move around which leads to sea of electrons

Question 41

# Periodic Trends Metallic

Answer 41

* Most = Bottom Left * Least = Top Right