Periodic Trends and Molecular Orbitals

Electron Affinity

Amount of energy released after an electron is gained

Electron Ionization

Amount of energy needed for an electron to be lost

Ionization behavior

Increases left to right (harder to lose and electron)

Electron Affinity behavior 

Increases left to right (easier to gain)

Zeff

What an electron feels taking into account sheilding and electron repulsion, more Zeff more stability

Zeff behavior

Increases left to right, stays the same down a period

Electronegativity

the ability for an atom to attract an electrons bonding pair

Electronegativity Behavior

Increases across a row, decreases down

Alkali Metals 

1st row, except for hydrogen 

Alkaline earth metals

2nd row

Transition metals

Row 3-11

Metalloids

Boron zigzag Si, Ge, As, Sb, Te

Halogens 

Row 17

Noble Gases

Row 18

Covalent Bonds

shared electrons, formed between two non metals

Atomic radius 

distance between shells and nucleus 

Atomic Radius Behavior

Decreases left to right and increases down a period

Core Charge

the attraction that the valence electron feels from the nucleus; # of protons - core electrons

Formal Charge

the middle atoms attraction; valence electrons - (bonds + lone electrons)

d

Row 1 - 2 and He

d

Row 3-12

p

row 13- 18 - He

f

bottom two rows 

ionic bonds

transferred electrons; non metal and metal