Nucleus Charge

Main Question or Discussion Point

I've got this following question which I don't really get:

What is the charge on the nucleus of each of the following? (assuming they are neutral)

a) Mg b) Ne c) K^+ d) S^2-

What I don't understand is the definition of "charge on the nucleus"

I am assuming that only protons have charge in the nucleus, therefore, I just count the number of protons and that gives me the charge on the nucleus.

This is what I think I'm supposed to do:

a) +12 b) +10 c) +19 d) +16

But then, would the charge be zero, because the electrons end up canceling the charge from the protons?

Or is there another way I'm supposed to do this?

Thanks,

Jason

mrjeffy321
I think you have the right idea to ignore the electrons.
The electrons are not in the nucleus, and thus should not effect the charge of the nucleus.

You can convert the charge of a single proton into 1.6021765 E-19 Coulomb or charge, rather than just "1", "2", ..., perhaps an answer in Coulomb is what it is looking for.

Gokul43201
Staff Emeritus
Gold Member
I've got this following question which I don't really get:

What is the charge on the nucleus of each of the following? (assuming they are neutral)
That last part is nonsensical.

a) Mg b) Ne c) K^+ d) S^2-

What I don't understand is the definition of "charge on the nucleus"

I am assuming that only protons have charge in the nucleus, therefore, I just count the number of protons and that gives me the charge on the nucleus.

This is what I think I'm supposed to do:

a) +12 b) +10 c) +19 d) +16
Neglecting the part of the question that I underlined (since it makes no sense), what you've done is perfectly correct !

But then, would the charge be zero, because the electrons end up canceling the charge from the protons?
Electrons are not contained in the nucleus; they should have nothing to do with this question.

Or is there another way I'm supposed to do this?
What you've done is the best that can be done. Good job !

And do let us know if your teacher says you're wrong.