Question

Which molecules show an appropriate number of bonds around each carbon atom?

1) Methane (CH₄)
2) Ethene (C₂H₄)
3) Ethyne (C₂H₂)
4) Propane (C₃H₈)

Answer 1

The molecules Methane (CH4), Ethene (C2H4), Ethyne (C2H2), and Propane (C3H8) all show an appropriate number of bonds around each carbon atom, as they comply with carbon's valency, which is four.

Step-by-step explanation:

The molecules that show an appropriate number of bonds around each carbon atom are:

1. Methane (CH₄): Methane is a simple organic compound where each carbon makes four single covalent bonds with hydrogen atoms, forming a tetrahedral shape. Each hydrogen atom lies at a corner of a geometrical tetrahedron with carbon at the center.
2. Ethene (C₂H₄): Ethene, also known as ethylene, has a double bond between the two carbon atoms. Each carbon atom forms two single bonds with two hydrogen atoms and one double bond with another carbon atom, summing up to four bonds.
3. Ethyne (C₂H₂): Ethyne, also known as acetylene, contains a triple bond between two carbon atoms. Each carbon atom also forms a single bond with a hydrogen atom, leading to four bonds around each carbon atom.
4. Propane (C₃H₈): Propane is an alkane with single bonds only. Each carbon atom forms four single bonds - either with hydrogen atoms or with other carbon atoms, in a chain of three carbon atoms.

All these molecules comply with the rule that carbon atoms form four bonds in total, as dictated by carbon's valency.