Electronic structure of atoms

wave-particle duality

behave like particles and waves depending on how you observe it

electromagnetic radiation

light and radiation are generated by particles moving through space in various wave patterns

wave length

width between peaks of a wave

Frequency

wave repetition

measured in Hz or 1/s

electromagnetic spectrum

mapped out wavelengths

new unit

angstrom

10^-10

quantized

stepwise rather than continuous

The photoelectric effect

a minimum frequency of light is required for the emission of on electron of a metal surface

photons

behave like “packets” of energy

absorbtion

energy is absorbed

high quanta

Emission

a photon is emitted

low quanta

continuous spectrum

A spectrum with continuous color 

Line spectrum

contains radiation from specific wavelengths

Bohr Model

Used to calculate spectral lines

uses quantized energy to describe the line spectra of the H atom

Energy of transitions

Energy change from transitions between energy levels

absorption or emission

photons in quantum mechanics

they are very small and move very fast which is why classic mechanics cant explain there behavior

Orbitals

the most likely location of the electron in a 3D space

Quantum numbers

behave like a road map to describe the orbit of an electron

principal quantum number (n)

determines size and energy of an orbital

n= 1, 2, 3, …

higher n = higher energy

Angular Quantum number (l)

Shape of orbital

range from 0 to n-1

if n = 3 then l = 0, 1, or 2

S orbital

l = 0

zero nodes: point where wavelengths = 0

P orbitals

l = 1

1 node

D orbital

l = 2

2 nodes

F orbital

l = 3

3 nodes

Magnetic quantum number (m_l)

Determines orientation of the orbital in space

range from -1 to 1

if l = 1 then m_l = -1, 0, 1

Spin quantum number (m_s)

spin of electrons

can be + ½ or - ½

spin down or spin up

shown through the arrows om Hund’s rule

Electron Configurations

use quantum numbers to understand electron arrangement in atoms

Pauli Exclusion Principal

states that no 2 electrons have the same set of quantum numbers

each magnetic quantum number (m_l) space can only have 1 spin up and 1 spin down electron

Hund’s Rule

When filling degenerated (equal energy or same n and l) orbitals the lowest energy is maximized when the electron having the same spin is maximized

for same angular quantum number (l) , fill the spin up first, then continue with spin down

Electron configuration: how to

1. atomic number

2. determine n

s & p blocks = row number

d blocks = row number -1

f blocks = row number - 2

3. determine the orbital

4. determine number of electrons in orbital (block)

turn into exponents

5. start with first electron (H) and fill until you reach element of interest

condensed electron configurations

shorten electron configurations by using condensed electron configurations

summarize last full p⁶ orbital as a noble gas in brackets

core electrons

electrons not involved in chemical bonding

valence electrons

electrons involved in chemical bonding

highest n value

has a completely filled shell

anomalies

shifts around electrons to become more stable

elements are happiest when shells are full or half full

d⁴ and d⁹ elements will re arrange electrons to accommodate for this

Electron configurations of Ions

When elements gain or lose electrons their electron configurations must be altered 

Isoelectronic

atoms that have the same electron arrangement