Chapter 8- Lewis Structures

single bond

a chem bond that results when two atoms share one pair of electrons

duet rule

hydrogen atoms, along with helium, achieve stability by having two electrons in their outermost (valence) shell

octet rule

chemical principle stating that atoms tend to gain, lose, or share electrons to achieve a stable configuration of eight valence electrons, just like noble gases

double bond

chem bond in which two atoms share two pairs of electrons

triple bond

two atoms share three pairs of electrons

bond order

number of bonds between two atoms

(1 for a single bond etcetera)

bond lengths

have an inverse relationship with bond order

• higher bond order = shorter bond length = stronger bond

free radicals

odd-electron molecules with an unpaired electron in its Lewis structure

electron deficient elements

Be and B tend to have less than 8 electrons

• 6 e- around Boron is stable

complete the octet around the ____ element first

more electronegative

hypervalent molecules

elements with 3 or more valence orbitals can expand their octet

if you have more than one potentially hypervalent, put the extra electrons on

the central atom

in a lewis structure, double headed arrow is

resonance

calculating formal charge

atom gets “full credit” for lone pairs (2 electrons)

atom gets “half credit” for bonded pairs (1 electron)

negative charges should go on the ___ ———— atom

most electronegative

dipole moment

measures a molecule's overall polarity, or how its positive and negative charges interact