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HW 2A.9 part (a)

Posted: Tue Nov 05, 2019 3:54 pm
by Charysa Santos 4G
Why would the M^2+ metal for [Ar]3d^7 be Co^2+? Shouldn't it be Cu^2+ since the metal in question supposedly lost 2 electrons and now has the electron configuration [Ar]3d^7?

Re: HW 2A.9 part (a)

Posted: Tue Nov 05, 2019 3:57 pm
by Charysa Santos 4G
And also, can someone explain why this also applies to part (b), and why it is Fe^2+?

Re: HW 2A.9 part (a)

Posted: Tue Nov 05, 2019 3:59 pm
by Alex Tchekanov Dis 2k
This is because the electron configuration for neutral Co is [Ar]3d74s2 and when you take off electrons, you take them from the 4s level instead of the 3d because the 4s is technically in a lower energy state. For these problems, it always helps to write the neutral configuration first and then take off electrons.

Re: HW 2A.9 part (a)

Posted: Tue Nov 05, 2019 4:04 pm
by Charysa Santos 4G
Ah, so because it's asking for a +2 metal, the ion's electron configuration for the d orbital is still the same as the neutral atom's because you're taking the 2 electrons from the s orbital... Understood!