Science (086) — AI-generated practice question

Carbon has 4 valence electrons and needs 4 more to achieve noble gas configuration. Forming ions is not feasible because:

(i) Gaining 4 electrons to form C⁴⁻ would be difficult, as the nucleus with only 6 protons cannot hold 10 electrons stably.

(ii) Losing 4 electrons to form C⁴⁺ would require a very large amount of energy, leaving 6 protons holding just 2 electrons.

Therefore, carbon overcomes this problem by sharing its 4 valence electrons with other atoms, forming covalent bonds. This allows both atoms to achieve noble gas configuration without gaining or losing electrons.

Source: Chapter 4, Section 4.1 — Bonding in Carbon: The Covalent Bond

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Examiners look for three specific points matching the 3 marks:

1. Why gaining 4 electrons is not possible (nuclear attraction too weak for C⁴⁻).
2. Why losing 4 electrons is not possible (too much energy needed for C⁴⁺).
3. The conclusion — carbon shares electrons, forming covalent bonds instead.

Avoid vague answers like "carbon is non-metal." Use the exact reasoning from the textbook. The terms C⁴⁻, C⁴⁺, and sharing are key scoring terms.