can anyone help me out I was cleaning my bike but broke a part could someone tell me it's name or where I could buy a new one from it goes near the chain like a protector so the metal doesn't get scratched by the chain

 

Are you sure you've broken it? cos these things usually are a push fit or at most a single screw to hold them in place. Oh and it's usually called " swing arm chain guard" if it's what I think your talking about NOT a THINGY!

Just so you know it's usual to say "Hi" in the new member section before you ask a "how do I fix my bike" question and it helps if you fill in all the details of what bike you have and where you live so we don't tell you to buy your part in Scunthorpe and you live in Timbuktu. plus next time say what bike it is at least as this helps as well. Just sayin. 

Welcome to the YOC  by the way it's good for folks to join these sort of forums as we have a wealth of knowledge and like to help out if we can.