Can someone please explain me? I have some questions about the Periodic Table...(sorry for any grammar mistake)

In the tranzition metals groups : group 3(IIIB) , group 4(IVB)...,group 7,8and 9(VIII B), group 11 (IB) , group 12(IIB)

Why groups 7,8,9 are all VIIIB?

And what does the "B" represent?

Why does the tranzition metals series start with III B and end with I B and II B?

And why group 13 is still IIIB?

And...in the groups 1,2,14,15,16,17,18 , what does the "A" represent ( I A, IVA , V A, VI A , VII A , VIII A)

1 Answer
Truong-Son N.
Mar 30, 2018

Well, first of all, groups 8, 9, and 10 are VIIIB, not 7, 8, and 9...

http://knowthatplace.com/http://knowthatplace.com/

If you just count the columns, then "IA", "IIA", "IIIB", "IVB", . . . , "VIIIB" just increases in roman numeral from 1 to 8, and similarly, "IA", "IIA", "IIIA", . . . , "VIIIA" does as well. That's how Mendeleev did it back then, without the "A" and "B".

"A" is CAS style notation and indicates main group elements, and "B" indicates... not main group, i.e. transition metals. More often, it is used in America.

The transition metals start at "IIIB" since that is the maximum oxidation state of "Sc". The name of the groups for the "Fe", "Co", and "Ni" families don't suggest that, however, and group "IB" does not tell us that the maximum oxidation state of "Cu" is often cited to be +2, not +1.

Related questions
Impact of this question
766 views around the world
You can reuse this answer
Creative Commons License