No, they wouldn't - the nature of neutron stars and black holes is that their gravitational pull is so strong it pulls matter so close that it overcomes the natural repulsion from their orbiting electrons. At this stage the matter is condensed so densely that there are no atoms anymore - electrons are pressed back into protons to create nothing but neutrons. If the mass is great enough it even pulls the matter in closer and eventually the matter occupies no space at all - this is a black hole.
wouldn't they be made of iron and helium which is what the stars that formed them would be composed of by the end of their life cycle
No, they wouldn't - the nature of neutron stars and black holes is that their gravitational pull is so strong it pulls matter so close that it overcomes the natural repulsion from their orbiting electrons. At this stage the matter is condensed so densely that there are no atoms anymore - electrons are pressed back into protons to create nothing but neutrons. If the mass is great enough it even pulls the matter in closer and eventually the matter occupies no space at all - this is a black hole.