What type of bonds link alkanes, leading to their low polarity?

Alkanes are saturated hydrocarbons, which means they consist entirely of single bonds between carbon atoms. These bonds are specifically sigma bonds, which are formed by the head-on overlapping of atomic orbitals. Sigma bonds allow for free rotation around the bond axis and result in a stable structure.

The low polarity of alkanes can be attributed to the nature of the carbon-hydrogen and carbon-carbon bonds. The electronegativity difference between carbon and hydrogen is relatively small, making C-H bonds only slightly polar. Similarly, C-C bonds also exhibit minimal difference in electronegativity, leading to nonpolar characteristics. As a result, the overall molecule remains nonpolar due to the symmetry and uniform charge distribution throughout.

This characteristic bond structure of alkanes—comprising primarily of single sigma bonds—contributes significantly to their low reactivity and low polarity. Hence, the correct link between the structure of alkanes and their low polarity is through the presence of single sigma bonds.