Can someone explain the oxidation selection on calculating electrons as noted

• Oct 18th 2010, 11:00 AM
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??
• Oct 18th 2010, 11:13 AM
Unknown008
You only need to vary the number of electrons.

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

\$\displaystyle ^{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.
• Oct 18th 2010, 11:19 AM
e^(i*pi)
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
• Oct 18th 2010, 11:28 AM
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.
• Oct 18th 2010, 11:32 AM
e^(i*pi)
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