excess cyclopentane + bromine + UV light?

Question

Why bromocyclopentane and HBr are the only products?
Will other H in cyclopentane being substituted by Br? Under what conditions?
Thank you!

Answer 1

If the cyclopentane is in excess, then that will tend to limit the reaction to one H being replaced by a Br atom.
If the proportion of Br is increased, then more H atoms can be substituted.