Chemistry Corner

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That's right, C₁₀H₂₂ is a hydrocarbon molecule of some kind, perhaps decane. Each molecule of decane contains ten carbons and 22 hydrogen atoms. Molecular compounds are not made of positive and negative ions, so we can eliminate CaO, and ionic compound. The elements gold and carbon exist as extended networks of atoms bonded together in some kind of structure, but these networks are essentially infinite with no molecular unit. A molecule consists of a specific number of atoms bonded together with covalent bonds. As such, molecular compounds are usually made of nonmetallic elements.

The graphite and diamond forms of carbon are not molecular because there are no molecular units in these forms of carbon. The atoms extend in practically an infinite array in the solid. But buckyball, C₆₀, is a molecular form of carbon, existing as soccer ball-shaped carbon molecules containing 60 carbon atoms specifically. So if the question said "C(buckyball)" then that would have been molecular too.

Steve

I was looking over some past messages and happened to notice in this question that I overlooked the word "solid" in the question. Decane is a molecular compound all right, but it is not a solid at room temperature (its melting point is �?9.7°C). So for the original question, which of the given compounds is a molecular solid, I would say none. I don't think there is another isomer of decane that is a solid at room temperature either.

Graphite is a solid and is made of carbon atoms covalently bonded to each other like molecular compounds, but it has no definite formula, unlike molecular compounds.

Only two months too late....

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