Question

what are hydrocarbons? how many types of Hydrocarbons are there? explain.​

Answer 1

hydrocarbons are the unburnt carbon particles released due the combustion of fuels.these when combined with atmospheric moisture forms smog.

they are divided into 3 main groups:- alkanes, alkenes, and alkynes.

Alkanes have only single bonds

Alkenes contain a carbon-carbon double bond

Alkynes contain a carbon-carbon triple bond.

Answer 2

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. 
There are several types of aliphatic hydrocarbons: alkanes,alkenes, alkynes and alkenynes.
Alkanes are linear, or branching, compounds that are made of varying numbers of carbon atoms that are all saturated with hydrogen atoms. The formula for an alkane is CnH(2n+2).
an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond. The words alkene and olefin are often used interchangeably. 
alkane is an unsaturated hydrocarbons that contains at least one carbon-, Carbon triple bond. the simplest acyclic alkynes with only with only one triple Bond and no other functional group form a homologous series with the general chemical formula CnH2n−2. Alkynes are traditionally known as acetylenes, although the name acetylene also refers specifically to C2H2, known formally as ethyne using IUPAC nomenclature. Like other hydrocarbons, alkynes
aregenerally hydrophobic but tend to be more reactive.

alkanyne are a cyclic branched or unbranched hydrocarbons having one carbon- carbon double bond and one carbon -carbon triple bond