Answer:
alkenes and alkynes are considered as unsaturated hydrocarbons because they are capable of reacting with hydrogen in the presence of a catalyst to form a saturated hydrocarbon (alkanes)
Explanation:
A saturated compound contains a chain of carbon atoms joined by single bonds, with hydrogen atoms attached to each carbon atom.
Propane for example, CH₃-CH₂-CH₃.
It is saturated because all the carbon atoms holds maximum number of hydrogen atoms.
Alkenes such as Propene (CH₂=CH-CH₃) and alkynes like Propyne,
(CH₃-C≡C-H) are unsaturated because the central carbon atoms contain less number of hydrogen atoms than they possibly could.
