In this case, we must remember that group VIIA elements are known as halogens which include F, Cl, Br, I and At. Now, when an alkane reacts with the diatomic form of one of those halogen a haloganation chemical reaction occurs forming an alkyl halide and a hydrogen halide. For instance, for ethane, if it reacts with iodine, ethyl iodide and hydrogen iodide are yielded based on the given example:
Alkanes are saturated hydrocarbon, that is they contain hydrogen and carbon without a double or triple bond between the carbon atoms, e.g. ethane, propane. Group 7a in the periodic table are called halogens e.g chlorine, bromine. Alkanes react with halogens in a reaction called substitution, where halogens replace hydrogen atoms in alkanes.
