In a certain organic compound, one of the carbon atoms is bonded to four atoms. One of these is a carbon atom, and the other three are hydrogen atoms. What type of bond exists between the two carbon atoms?

A. Ionic

B. Dispersion force

C. Double covalent

D. Single covalent

Between the two carbon atoms exists a single covalent bond. In the question, it tells us that in a compound, one of the carbon atoms is bonded to 4 others, one of them being another carbon and the rest all hydrogens. We can deduce the compound is actually C2H6, which is an alkane; specifically ethane.

Alkanes are saturated hydrocarbons and as such can only have single carbon-carbon bonds since both are bonded with 3 other atoms (leaving them with no spare electrons as they only have 4).