Question

Confused.
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Answer 1

I looked at this, and my first inclination is that the the number of protons does not change. we have essentially an ion right? we can easily figure out the number of protons by going to the periodic table.

This was the strategy I had in mind.

if the number of protons changed we wouldn't have the same element. so that's where we start. Now that we've identified this, we need to figure out how many electrons we have. the number of electrons usually equals the number of protons in neutral atoms, but now it doesn't because we have a +2 charge.

+2 essentially means that we've lost two electrons, which isn't surprising because metals like to do this, they like losing electrons.

we can figure this out by subtracting 2 from the atomic number to find the number of electrons. so essentially there are 26 electrons and 28 protons, that's where the +2 charge comes from, the electrons are held more tightly by the increased positive charge.

now I think all we need to do is to subtract the mass number the atomic number. we still have 28 protons so We'd have to subtract this from the mass number.


hopefully you'll be able to decipher this poorly drawn figure