Chemistry Week 6

octet rule

Atoms will gain, lose, or share electrons to become isoelectronic with a noble gas. Beryllium and Boron don’t follow the octet rule.

lone pairs

pairs of valence electrons that are not involved in covalent bonding

single bond

when one pair of electrons is shared between atoms

double bond

when two pairs of electrons are shared between atoms

triple bond

when three pairs of electrons are shared between atoms

bond length

distance between the nuclei of covalently bonded atoms

polar covalent bonds

bonds where electrons are not shared equally, creating partial positive and negative charges

electronegativity

the ability of an atom to draw shared electrons to itself. Increases left to right and decreases top to bottom on the periodic table

What difference in electronegativity corresponds to a nonpolar bond?

<0.5

What difference in electronegativity corresponds to a polar bond?

0.5<…<2.0

What difference in electronegativity corresponds to an ionic bond

2.0<

dipole momement

quantitative measure of polarity

dipole moment equation

M=Qxr

Debye unit equation

D=3.34×10^-30C(m)

Coulombs equation

1e=1.6×10^-19

Formal Charge

the valence electrons an element has on the periodic table minus the electrons assigned to it on the periodic table

resonance structure

one of multiple equally valid Lewis structures for a molecule

coordinate covalent bond

a covalent bond where one atom shares both electrons

Lewis base

an atom that donates two electrons in a coordinate covalent bond

Lewis acid

an atom that accepts two electrons in a coordinate covalent bond

free radical

highly reactive molecules with an odd number of electrons

expanded octets

additional octets formed using electrons from the d subshell