Why are there multiple products produced from the halogenation of alkanes?

Answer 1

This depends on the type of halogenation - with chlorination you tend to get multiple products - this is because chlorination is a exothermic reaction - the activation barrier for the primary secondary and tertiary radicals are close

For bromination it is more selective than chlorination - this is due to being endothermic and the barriers for tertiary are much higher than secondary than primary.