MCAT General Chemistry

Rutherford Model

1911, electrons surround the nucleus

Bohr model

1913, orbits with energy levels with more energy in further energy levels

heisenbug uncertainty

impossible to know momentum and position at the same time

Hund’s rule

electron only doubles up in orbitals if all orbitals have 1 electron

Pauli exclusion principle

Paired electrons must be +1/2 and -1.2

Avogadros Number

6.022 × 10²³ = 1 mol

Planck’s constant

6.026 × 10^-34J*s

speed of light

3 × 10⁸ m/s

Light Energy

Atomic format

Diamagnetic

All electrons are paired and repelled by an magnetic field

paramagnetic

1 or more unpaired electrons and pulled into external magnetic field

Quantum numbers

n, l, m_i, m_s

n

Principal and shows energy level. Only for s and p

l

azimuthal, shape of orbital

m_i

magnetic and orbital subtype 1,+-1,+-5, +-7

m_s

spin, electron spin only +-1/2

Free radical

atom or molecule with unpaired electron

Aufbau principle

Zeff

pull between nucleus and valence electrons and increases along period

Ionization energy

Energy needed to release electrons. Increases across period and decreases down group

Electronegativity

Force atom exerts on electron in a bond. Increases across period and decreases down group

Electron affinity

Ability to gain electrons and increases along period

Covalent bond

sharing of electrons

Bond order

type of bond, gets stronger and shorter with more bonds

Nonpolar bonds

<0.5

Polar bonds

Between 0.5 and 1.7

Coordinate covalent bonds

single atom providing both bonding electrons

Ionic bond

transfer of electrons with it greater than 1.7

H bonding

Strongest with OH, NH, or FH

Dipole-Dipole

Polar non hydrogen bond

LDF

Temporary non polar

Equivalent Mass

mass of an acid that yields 1 mole of H+ or mass of base that reacts with one mole of H+

Equivalents and normality

Types of reactions

1. combination

2. decomposition

3. combustion

4. single displacement

5. double displacement

6. neutralization

0 order

1 order

2 order

Arrhenius equation

Rate law misc