Which of the following are isotopes? a u-235, br-81 b mg-12, mn-55 c cl-35, cl-37 d h-1, h-1

C) Cl-35 & Cl-37

Explanation:

Isotope: a form of an element that differs only in the number of neutrons in the nucleus.

A & B are wrong because U and Br are two different elements, so are Mg and Mn.

D is a trick question because H-1 is the same as H-1, therefore they can't be isotopes.

if you're asking what comes out, it's steam.