Unit 2: Bonds

Ionic bond

when an element with high electron affinity and one with low electron affinity transfer electrons, creating a strong bond. Metal and nonmetal. electronegativity difference >1.8

Covalent bond

when electrons are shared by two atoms. Two nonmetals

Polar vs nonpolar covalent bonds

creates areas of partially negative and partially positive charge. electronegativity difference 0.4-1.8 is polar, <0.4 is nonpolar

periodic trend for electronegativity

increases up and to the right

metalic bonds

form between metal cations with delocalized valence electrons

octet rule

certain elements prefer to be surrounded by 8 electrons (C, N, O)

stablility of elements

neutral atoms are more stable than + or -. Full octets are stable.

Valence Shell Electron Pair Repulsion (VESPR theory)

lone pair and/or electrons will be as far away from each other as possible.

electron domains

Assuming no lone pairs; 2 = linear, 3 = trigonal planar, 4 = tetrahedral

assessing polarity

if a net dipole exists, the bond is polar.