Answer and explanation:
Let's review the concepts of saturated and unsaturated hydrocarbons:
- Saturated hydrocarbons contain only single covalent bonds, which means that the type of bonds is simple bonds. It is called saturated hydrocarbons because we contain more hydrogens in the molecule than an unsaturated hydrocarbon.
- Unsaturated hydrocarbons contain double or triple covalent bonds in the molecule, so it contains less hydrogen atoms in their structure and that's why they are called unsaturated hydrocarbons.
Now, let's see the structure of ehtene:
You can realize that we have 1 double bond between two carbons, so ethene would be an unsaturated hydrocarbon.