for the equation:
propane + bromine
how do I know on which carbon the Br would attatch itself to.
2 answers
It can attache to any of them, forming different compounds. But in the case of propane and bromine, the great majority of the product will be with one bromine attached to the central carbon. In the case of chlorine, the mix of compounds is about equal. Besides the monobromide compounds, there is an array of bromide compounds with more than one bromine atom. Don't try this reaction with fluorine, it is rather dangerous.
Thank you soo much :) and I`ll keep in mind what you said about fluroine.