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atomic number = protons.
protons+neutrons=atomic mass.
170 (mass) - 41 (proton/number) = 129
that should be ur answer. I hope this helps!
Mg is a metal. Under ordinary conditions it will not form a diatomic molecule. The other 3 are non metals. They come from the right side of the periodic table and they willl form diatomic molecules.
Isotopes of carbon or any element
