In high school I am taught that Group 7 were halogens and Group 8 were noble gases, and Group 3 the boron group, Group 4 was carbon group, etc. Then when I looked up the groups, I found that noble gases were group 18, halogens were group 17, Group 7 was the manganese group, ...

The school said that their numbering is based on counting valence electrons, and the transition metal columns have no business in their lessons.

So schools don't use IUPAC conventions.

How standard is their group name scheme?

  • $\begingroup$ Surely this is primarily opinion-based? $\endgroup$ Commented Jun 13, 2017 at 10:42
  • $\begingroup$ In Germany, the answer would be: "Schools are extremely slow to change their curriculae". Like in "We still only teach pre-1650 mathematics because we don't know yet how to teach children modern concepts of mathematics"-slow $\endgroup$
    – user37142
    Commented Jun 13, 2017 at 11:15

1 Answer 1


The reason for this is that in 1988 (actually more than a few years back), IUPAC changed their naming system for the groups. Originally the transition metals didn't have a group number and weren't counted as a group. However now it is changed so that the transition metals do have a group number. So number instead of carbon being in group 4, it is in group 14. However despite this being changed quite a few years ago, you will still see in several websites and schools like your and mine still following the old IUPAC conventions and say that carbon is in group 4 rather than 14.

The reason that they do this I suppose is that it avoids confusion in students who are just picking up chemistry as they can see there is a clear relationship between valence electrons and group number. However besides this, schools do follow IUPAC conventions.


Pure Appl. Chem. 1988, 60, 431–436, DOI: 10.1351/pac198860030431

(thanks @Loong)

  • $\begingroup$ So it was old IUPAC after all. Changed title to reflect this. $\endgroup$ Commented Oct 14, 2015 at 4:09
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    $\begingroup$ Expanding on the argument, the periodic tables at my school always used roman numerals for group numbers and the transition metals had group numbers with a lowercase b next to them, so halogens would be VII, boron group III and manganese in group VIIb. Now as far as I know, arabic numerals are used so no confusion should occur between 7, VII and VIIb. $\endgroup$
    – Jan
    Commented Oct 14, 2015 at 7:52
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    $\begingroup$ @Loong thanks for the correction. Yeah, I am pretty sure that 1988 wasn't a few years ago. I have edited my answer now. $\endgroup$
    – Nanoputian
    Commented Oct 14, 2015 at 19:45
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    $\begingroup$ @Nanoputian If you want to add a reference to your answer: Pure Appl. Chem. 1988, 60, 431–436, DOI: 10.1351/pac198860030431. $\endgroup$
    – user7951
    Commented Oct 14, 2015 at 19:59
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    $\begingroup$ I went to school so long ago that the only elements on the periodic table were earth, air, fire and water. // I'm incensed about the IUPAC change. Why did they discriminate against the actnides? $\endgroup$
    – MaxW
    Commented Nov 14, 2015 at 4:30

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