In which of the following bonding patterns does atom X obey the octet rule?

• A. X forms five single bonds with other atoms.
• B. X forms one triple bond and one single bond.
• C. X forms two double bonds with two different atoms.
• D. X forms four single covalent bonds with other atoms.

Answer: (D)

Verified step by step guidance

1. Recall the octet rule: an atom tends to form bonds until it is surrounded by 8 electrons in its valence shell, counting both bonding and lone pair electrons.
2. Calculate the total number of electrons around atom X in each bonding pattern by counting the electrons contributed by each bond. Each single bond contributes 2 electrons, a double bond contributes 4 electrons, and a triple bond contributes 6 electrons.
3. For the pattern where X forms five single bonds, multiply 5 bonds by 2 electrons per bond to find the total electrons around X. Compare this number to 8 to see if the octet rule is obeyed.
4. For the pattern where X forms one triple bond and one single bond, add the electrons from the triple bond (6 electrons) and the single bond (2 electrons) to find the total electrons around X. Check if this total equals 8.
5. For the pattern where X forms two double bonds, multiply 2 bonds by 4 electrons per bond to find the total electrons around X. For the pattern where X forms four single bonds, multiply 4 bonds by 2 electrons per bond. Compare both totals to 8 to determine if the octet rule is obeyed.