Test: Introduction To Hydrocarbons

They are position isomers. 
Position isomerism :- When two or more compounds with the same molecular formula differ in the position of substituent atom or functional group on the carbon atom, they are called position  isomers and this phenomenon  is termed as position isomerism.
 

Alkanes are saturated hydrocarbons having C-C single bond and general formula C_nH_2n+2.

Graphite can conduct electricity because in graphite every carbon atom is bonded to 3 other carbon atoms and has 1 free electron. This free electrons help in conducting electricity.

Butane is a saturated hydrocarbon. But + ane = Butane.

Carbon has the unique ability to form bonds with other atoms of carbon, giving rise to large molecules. This property is called catenation or self linking ability of carbon.