Molecular and Ionic Bonding

Two

Three

None

One

4

1

3

2

Fluorine (F2)

Nitrogen (N2)

Oxygen (O2)

Hydrogen (H2)

N2

CF4

NH3

CO2

The NH bond length is shorter than typical covalent bonds causing polarity.

The presence of a lone pair on nitrogen creates an asymmetrical charge distribution.

NH3 has delocalized pi electrons generating an uneven charge distribution.

Nitrogen has a lower electronegativity than hydrogen, leading to polarity.

Methane (CH4), due to weak London dispersion forces.

Neon gas (Ne), due to very weak London dispersion forces.

Hydrogen fluoride (HF), due to strong hydrogen bonding.

Carbon tetrachloride (CCl4), due to moderate London dispersion forces.

When both ΔH and ΔS are positive values.

When both ΔH and ΔS are negative values.

When ΔH is positive and ΔS is negative.

When Η is negative and S is positive.

The square planar geometry results in a nonzero dipole moment which is characteristic for XeF4 due to the polarity of Xe-F bonds.

The fluorine atoms and two lone pairs on xenon are arranged symmetrically around the central atom at right angles.

XeF4 displays a linear structure similar to CO2, making it suitable for discussing linear geometries despite being actually square planar.

Xenon being part of group 18 is not supposed to form stable compounds, properties like XeF4 make it an exception and interesting example.

Tetrahedral

Linear

Bent

Trigonal planar

NH3

O2

CCl4

N2