Why do covalent molecular substances such as methane have low melting points?
Answer and explanation
Correct answer: C. Only weak forces between molecules need to be overcome
- Step 1: On melting, the molecules separate from each other.
- Step 2: The forces between molecules are weak, so little energy is needed.
Answer
Only weak forces between molecules need to be overcome.
Why not the others: The covalent bonds inside the molecule are weak: the bonds are strong but are not broken on melting. Each atom has a full outer shell of electrons: this does not explain the melting point. The molecules contain ions: covalent molecules do not contain ions.
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