What is the average atomic mass of an element with isotopes a b and c?

What are the percent by mass of copper in penny lab

Each of the following compounds contains a metal that can exhibit more than one ionic charge. provide systematic names for each of these compounds. (a) cr(clo3)6 (b) mo(cn)6 (c) cr2(so3)3 (d) v(clo2)2 (e) v(cn)5 (f) os(clo2)4

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.