The following images show contours of constant electron density for H2 calculated using...

The following images show contours of constant electron density for H₂ calculated using the methods described in Chapter 26. The values of electron density are (a) 0.10, (b) 0.15, (c) 0.20, (d) 0.25, and (e) 0.30 electron/a³.

a. Explain why the apparent size of the H2 molecule as approximated by the volume inside the contour varies in the sequence a-e.

b. Notice the neck that forms between the two hydrogen atoms in contours c and d. What does neck formation tell you about the relative density in the bonding region and in the region near the nuclei?

c. Explain the shape of the contours in image e by comparing this image with Figures 23.9 and 23.10.

d. Estimate the electron density in the bonding region midway between the H atoms by estimating the value of the electron density at which the neck disappears.