Why are Na⁺ and K⁺ unable to form covalent bonds?

The N—F bond is more polar than the N—H bond, but NF₃ has a smaller dipole moment than NH₃. Explain this curious result.

NF₃

μ= 0.2 D

NH₃

μ = 1.5 D

For each of the following compounds,

1. draw the Lewis structure.

2. show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment.

3. estimate whether the compound will have a large, small, or zero dipole moment.

d.

For each of the following compounds,

1. draw the Lewis structure.

2. show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment.

3. estimate whether the compound will have a large, small, or zero dipole moment.

e.

The electrostatic potential maps for ammonia and water are shown here. The structure of ammonia is shown within its EPM. Note how the lone pair creates a region of high electron potential (red), and the hydrogens are in regions of low electron potential (blue). Show how your three-dimensional structure of water corresponds with its EPM.

Show the ionic compound that you would expect to form between the given metal and nonmetal. Label the charges on each species.

(b) Mg and Br

Give the charge most likely to result from ionization of the following metals.

(b) Aluminum

Without looking at Figure 2.20, use your intuition to estimate whether a bond is ionic, polar covalent, or covalent.

(a) Na―Cl

Show the ionic compound that you would expect to form between the given metal and nonmetal. Label the charges on each species.

(a) Al and F