Isotopes: are 24 12 mg, 25 12 mg, 26 12 mg isotopes of each other? Explain

Answer 1

This goes to show you how important it is to use the proper symbols/nomenclature/formulae, etc.

mg stands for milligrams, and it took me a minute to realize you meant magnesium, which is Mg.

So, the question becomes...

are ²⁴₁₂Mg, ²⁵₁₂Mg and ²⁶₁₂Mg isotopes of each other.

The answer is YES they are isotopes. The 12 indicates atomic number = #protons and this defines the element (Mg). So they are all Mg. The upper number (24, 25, 26) is the atomic mass which is the sum of the #protons + #neutrons. They each have a different number of neutrons, making them isotopes.