Chemistry Regents Practice Test

Saturated hydrocarbons are characterized by having only single carbon-to-carbon bonds. This means that every carbon atom in a saturated hydrocarbon, such as alkanes, is fully "saturated" with hydrogen atoms, leaving no room for additional bonds with other atoms. In contrast, unsaturated hydrocarbons have at least one double or triple bond between carbon atoms, which reduces the number of hydrogen atoms that can be attached to the molecule.

This fundamental difference in bonding structure directly influences the chemical properties and reactivity of these compounds. For instance, the presence of double or triple bonds in unsaturated hydrocarbons makes them more reactive compared to their saturated counterparts. As a result of these structural differences, it's clear that the distinguishing feature of saturated versus unsaturated hydrocarbons lies in their bonding—saturated hydrocarbons exclusively feature single bonds.