Why is $C$ able to form the backbone for such a wide variety of molecules?

• A. Because $C$ can form $4$ covalent bonds, allowing for a variety of stable structures such as chains, rings, and branches
• B. Because $C$ atoms are the largest atoms in the periodic table, making them highly reactive
• C. Because $C$ only forms ionic bonds, which are easily rearranged
• D. Because $C$ has a full valence shell and does not need to bond with other atoms

Answer: (A)

Verified step by step guidance

1. Recall that carbon (C) has four valence electrons, which means it can form up to four covalent bonds with other atoms. This tetravalency is key to its bonding versatility.
2. Understand that because carbon can form four bonds, it can create a variety of stable structures including long chains, branched chains, and rings by bonding with other carbon atoms or different elements.
3. Recognize that these covalent bonds are strong and directional, allowing for the formation of complex three-dimensional molecules essential for organic chemistry.
4. Note that carbon does not form ionic bonds predominantly; instead, it forms covalent bonds, which are more stable and allow for diverse molecular architectures.
5. Conclude that the ability of carbon to form four covalent bonds and create stable, diverse structures is why it serves as the backbone for a wide variety of organic molecules.