Covalent Bonding
noble gas
Group 18: Nonreactive family of nonmetals; 8 valence e- (full octet). All are gases at room temp.
diatomic elements
H2, N2, O2, F2, Cl2, Br2, I2 (Use the 7-up shortcut to help you!)
octet rule
States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons
trigonal planer
The shape of a molecule with three bonded atoms and no lone pairs
nonpolar covalent bond
a bond formed when the atoms in a molecule are alike and the bonding electrons are shared equally
polar covalent bond
a bond formed when the atoms in a molecule are different and the bonding electrons are shared unequally
polar bond
a bond formed when two different atoms are joined by a covalent bond and the bonding electrons are shared unequally
single covalent bond
a bond in which two atoms share a pair of electrons
polar molecule
a molecule, like water, in which one or more atoms is slightly negative and one or more is slightly positive, unless molecular geometry causes the polarities to cancel each other out
hydrogen bond
a relatively strong intermolecular force in which a hydrogen atom that is covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom in the same molecule or one nearby
linear structure
all atoms in a line O=C=O
triple covalent bonds
bonds that involve three shared pairs of electrons
double covalent bonds
bonds that involve two shared pairs of electrons
structural formulas
chemical formulas that show the arrangement of atoms in molecules and polyatomic ions; each "-" indicates one pair of shared electrons
octa-
eight
Bond energy
energy required to break a bond
penta-
five
Lewis Structures
formulas in which atomic symbols represent nuclei and inner-shell electrons, dot-pairs or dashes between two atomic symbols represent electron pairs in covalent bonds, and dots adjacent to only one atomic symbol represent unshared electrons
tetra-
four
nona-
nine
mono-
one
unshared pairs
pairs of valence electrons that are not shared between atoms; aka lone pairs or nonbonding pairs
octahedral
rule breaker
hepta-
seven
hexa-
six
resonance structures
structures that occur when it is possible to write two or more valid electron dot formulas that have the same number of electron pairs for a molecule or ion
deca-
ten
tri-
three
di-
two
VSEPR theory
valence-shell electron-pair repulsion theory; because electron pairs repel, molecules adjust their shapes so that valence-electron pairs are as far apart as possible
ALL HALOGENS AND HYDROGEN
1 bond ONLY
bent
2 atoms bonded to central atom 1 lone pair of electrons or 2 atoms bonded to central atom 2 lone pair of electrons
oxygen
2 bonds 2 lone pairs of electrons (element)
nitrogen
3 bonds 1 lone pair of electrons (element)
trigonal pyramidal
3 bonds, 1 lone pair
Group 14
4 Valence Electrons....needs 4 more to reach 8 4 Bonds no lone pair of electrons
carbon
4 bonds 0 lone pair of electrons (element)
trigonal bipyramidal
5 bonded atoms, 0 lone pairs
Group 15
5 valence electrons.......needs 3 more to reach 8 3 Bonds one lone pair of electrons
Group 16
6 valence electrons.......needs 2 more to reach 8 2 Bonds 2 lone pairs of electrons
Group 17
7 valence electrons.......needs 1 more to reach 8 1 Bond
electronegativity
A measure of the ability of an atom in a chemical compound to attract electrons
Bond
An attractive force acting between atoms
