A hydrocarbon in which two carbon atoms are joined by a double bond is called as an :

Explanation

Compounds containing only carbon and hydrogen are called hydrocarbons. Unsaturated open-chain hydrocarbons having a carbon–carbon double bond are called alkenes. Alkanes are saturated open-chain hydrocarbons having a carbon–carbon single bond. Alkynes are unsaturated hydrocarbons having a carbon–carbon triple bond. The bonds formed due to the transfer of electrons between atoms are called electrovalent bonds or ionic bonds. — C — , — C = C —, — C ≡ C Alkane Alkene Alkyne