IB Chemistry HL Topic 14 (Chemical Bonding and Structure)单词卡 | Quizlet

sigma bond

This type of bond is formed by head-on overlap of atomic orbitals, resulting in electron density concentrated between the nuclei of the bonding atoms.

pi bond

This type of bond is formed by the sideways overlap of atomic orbitals, resulting in electron density above and below the plane of the nuclei of the bonding atoms.

formal charge

a hypothetical charge worked out with the following equation: (number of valence electrons) - [(1/2)(number of bonding electrons)] - (number of nonbonding electrons)

single covalent bond

consists of two electrons shared between two atoms A and B; this bond is a sigma bond

double covalent bond

consists of four electrons (two pairs) shared between two atoms A and B; this bond is 1 sigma bond plus 1 pi bond

triple covalent bond

consists of six electrons (three pairs) shared between two atoms A and B; this bond is 1 sigma bond plus 2 pi bonds

incomplete octet

an element with fewer than 8 valence electrons (example: boron)

expanded octet

more than 8 valence electrons surrounding the central atom

Formal charge equation

FC=(# of valence electrons) - 1/2(number of bonding electrons) - (number of non-bonding electrons)

hybridization

a concept used in Valence Bond Theory to explain the number of bonds that an atom can form and the spatial orientation of these bonds; the mixing of atomic orbitals to generate hybrid orbitals that are equivalent

delocalization

electrons that are shared by/between all atoms in a molecule or ion as opposed to being localized between a pair of atoms

resonance

involves using two or more Lewis structures to represent a particular molecule or ion; structure is one of two or more alternative Lewis structures for a molecule or ion that cannot be described fully with one Lewis structure alone

sp3

4 electron domains (single bond)

sp2

3 electron domains (double bond)

sp

2 electron domains (triple bond)

possible overlap combinations: sigma bonding

s + s

s + px

px + px

possible overlap combinations: pi bonding

py + py

pz + pz

trigonal bipyramidal

5 electron domains

axial 90 degrees

equatorial 120 degrees

no lone pairs

5 BPs

seesaw

5 electron domains

axial >90 degrees

equatorial >120 degrees

1 lone pair

4 BPs

T-shaped

5 electron domains

90 degrees

2 lone pairs

3 BPs

linear (5 electron domains)

5 electron domains

180 degrees

3 lone pairs

3 BPs

octahedral

6 electron domains

90 degrees

0 lone pairs

6 BPs

square-based pyramidal

6 electron domains

90 degrees

1 lone pair

5 BPs

square planar

6 electron domains

90 degrees

2 lone pairs

4 BPs

s orbital shape

spherical

p orbital shape

dumbbell