Question

Caffeine is a natural insecticide found in the seeds and leaves of certain plants, where it kills insects that feed on the plant. Caffeine is extracted for human consumption from beans of the coffee plant, from Kola nuts, and from the leaves of tea plants. Because it stimulates the central nervous system, it temporarily prevents drowsiness. Add caffeine’s missing lone pairs to its structure.

Short answer

The lone pair of electrons is the electron that does not participate in bonding.

Step-by-step solution

Understanding lone pairs.

The lone pair of electrons is the electron that does not participate in bonding.

Calculating the lone pairs of electrons.

We need to count the number of bonds formed by the atoms and then see whether they follow the octet rule. In order to calculate the number of lone pairs, we have to subtract the electrons on bonded atoms from the 8 following the octet rule.