Final answer:
Saturated fatty acids have only single bonds and are solid at room temperature, while unsaturated fatty acids have double bonds and are liquid at room temperature.
Step-by-step explanation:
Saturated fatty acids contain only single bonds along the length of the carbon chain and are fully saturated with hydrogen atoms.
They are solid or semi-solid at room temperature. Examples of saturated fatty acids include palmitic acid and stearic acid.
On the other hand, unsaturated fatty acids contain one or more double bonds along the carbon chain.
They are liquid at room temperature. Examples of unsaturated fatty acids include oleic acid and linoleic acid.