C5h12 with one tertiary carbon

See attached image.

Explanation:

Hello there!

In this case, according to the isomeric structure of hydrocarbons, it is possible to draw a five-carbon hydrocarbon with a tertiary carbon by keeping in mind these tertiary carbons are characterized by the presence of three bonds with carbon atoms.

In such a way, as shown on the attached image, the second carbon from left to right is tertiary because of the aforementioned, and also, the compound has five carbon atoms and twelve hydrogen atoms.

Best regards!

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.