Chemistry Last Minute Study

Electronegativity

tendency to attract to a bonding pair of electrons (increase left to right and up)

Effective nuclear charge

charge pulling electrons towards the nucleus (increase left to right and up)

Electron affinity

amount of energy released when an electron attaches to a neutral atom in the gas state

(X(g) + e- → x-)

(increase left to right and up)

ionization energy

amount of energy needed to remove an electron

(3rd IE is higher than 2nd, 2nd higher than first because effective nuclear charge increases as electrons are removed pulling it closer to the nucleus)

atomic radius

size of an atom (decreases left to right and up)

ionic radius

radius of an ion in a crystal lattice (decreases left to right and up)

ionic radius vs atomic radius

• ionic radius of a POSITIVE ion is SMALLER than atomic radius

• ionic radius of a NEGATIVE ion is BIGGER than atomic radius

polarizability

larger molecules are more polarizable than smaller ones (decreases left to right and up)

lattice energy

increases with increasing ionic charge and decreasing ionic size

Hunds

electrons fill each orbital once before putting another

Aufbau

electrons occupy lowest to highest energy levels