Bonds and Bond Types

Ionic

Metal to nonmetal, oppositely charged held by electrostatic attraction

Covalent

Non-metal to non-metal

Electron Geometry Steric (# of groups) number of 2

Linear: 180-degree angle

Steric (# of groups) number of 3

Trigonal planar: 120-degree angle

Steric (# of groups) number of 4

Tetrahedral: 109.5-degree angle

Steric (# of groups) number of 5

Trigonal bipyramidal: 90-degree or 120-degree

Steric (# of groups) number of 6

Octahedral: all angles 90-degree or 120-degree

3 electron dense regions, 1 lone pair

Bent/angular (<120 degrees)

4 electron dense regions, 1 lone pair

Trigonal pyramid (<109.5)

4 electron dense regions, 2 lone pairs

Bent or angular (<<109.5)

5 electron dense regions, 1 lone pair

Seesaw (<90 <120)

5 electron dense regions, 2 lone pairs

T-shape (<90)

5 electron dense regions, 3 lone pairs

Linear (180)

6 electron dense regions, 1 lone pair

Square pyramid (<90)

6 electron dense regions, 2 lone pairs

Square planar (90)

6 electron dense regions, 3 lone pairs

T-shape (<90)

6 electron dense regions, 4 lone pairs

Linear (180)

Pure covalent (nonpolar), Electronegativity difference is

< 0.4

Polar covalent, Electronegativity difference is

Between 0.4 and 1.8

Ionic, Electronegativity difference is

> 1.8

Pure Covalent

Neutral atoms held by equally share electrons

Polar Covalent

Partially charged held together unequally

2 electron density regions

linear (sp)

3 electron density regions

trigonal planar (sp²)

4 electron density regions

tetrahedral (sp³)

5 electron density regions

Trigonal bipyramidal (sp³d)

6 electron density regions

Octohedral (sp³d²)

Order of orbitals

(σ_2s)² (σ*_2s)² (σ_2p)² (π_2px, π_2py)⁴ (π*_2px, π*_2py)⁴

Lattice energy

group 2 has high af lattice energy

Effective Nuclear Charge

Increases left to right bottom to top

Asymmetrical

polar

Symmetrical

non-polar

Effective nuclear charge

magnitude of positive charge “experienced” by an electron in the atom, increases left to right

Ionization Energy

minimum energy required to remove an electron from an atom, increases left to right

No lone pairs on the central atom, and bonded atoms are of the same element

Molecule is usually non-polar

No lone pairs on the central atom, and bonded atoms are of different elements

Molecule is usually polar

Lone pairs on the central atom

Molecule is usually polar

Only C and H atoms

Molecule is usually non-polar

Molecule with C and H atoms but having one or more different atoms

Molecule is usually polar