# Math Help - Can someone explain the oxidation selection on calculating electrons as noted

1. ## Can someone explain the oxidation selection on calculating electrons as noted

Ok. I am studying my notes and have a question on # of p,f and e.

Atom of Nitrogen-14 = 14 over 7 N p=7 n=7 e=?
net charge/oxdation 2,+-3,4,5

Atom of Iron -256 = 56 over 26 FE p=26 n=30 e??
net charge 2,3

Atom of Uranium-256= 236 over 92 U p=92 n=144 e=
net charge 3,4,5,6

I am to write the nuclide symbol and state the number of p,n,e.
Question I have is how do I know which charge to use to calculate the electrons?

If there is a negative # I use that one, but if it's only positive, which one do I use like in U and Fe??

2. You only need to vary the number of electrons.

$^{14}_7 N^{3-}$ has 7 + 3 electrons (so that there are 3 more electrons than protons, thus a net charge of 3-)

$^{14}_7 N^{3+}$ has 7 - 3 electrons (so that there are 3 less electrons than protons, thus a net charge of 3+)

Try out the others now.

3. In all atoms the number of electrons is equal to the number of protons. This holds for isotopes which only vary in terms of neutron number.

Net charge = atomic number - number of electrons.

For positive charges there are more protons than electrons and for negative there are more electrons. With regards to my first statement when there is a net charge the species is an ion

Oxidation numbers are a different aspect of chemistry used in compounds, I do not understand what they have to do with the question here

4. Hi, OK I worded it wrong on saying oxidation numbers. It's ion which I understand. So if the net charge is + there will be less electrons. And if the net charge is - there will be more electrons correct?? I am just making sure I understand this.

But I guess what I mean above is that if you have 3 net charges to select from. which one do you use? I an kinda unclear about that. I am looking at my notes in my book and I.
Like the Uranimum. I can have 4 different electrons depending on the one I select? There is something simple here, but it's not clicking in my mind here.

5. Originally Posted by bradycat
Hi, OK I worded it wrong on saying oxidation numbers. It's ion which I understand. So if the net charge is + there will be less electrons. And if the net charge is - there will be more electrons correct?? I am just making sure I understand this.
Correct

But I guess what I mean above is that if you have 3 net charges to select from. which one do you use? I an kinda unclear about that. I am looking at my notes in my book and I.
Like the Uranimum. I can have 4 different electrons depending on the one I select? There is something simple here, but it's not clicking in my mind here.
From reading the question I believe it's asking you to state the number of protons, neutrons and electrons in each case.