How are groups named in the periodic table?

 The groups in the periodic table are now numbered, not named, according to the latest recommendations of IUPAC.

They are numbered 1 to 18 from left to right in the periodic table, as there are 18 groups in the modern periodic table of elements. This is the new naming convention/system adopted by IUPAC. The older system of naming the groups has however, not lost its significance, and it should be learnt also.

The older naming system names the groups using Roman numerals and English alphabets 'A' and 'B'. The groups from left to right in the periodic table are named as follows:

IA, IIA, IIIB, IVB, VB, VIIB, VIIIB, IB, IIB, IIIA, IVA, VA, VIA, VIIA, VIII group.

The noticeable thing in the above naming system is that :

• One, there are only 16 groups here. This is because the group named VIIIB contains three vertical columns (columns 8^th, 9^th and 10^th of the current periodic table) which makes a total of 18 columns.
• There are two letters A and B used in this system. This is a was of classifying the elements. The letter A is used to represent the “Representative elements” and the letter B is used to represent the “Transition elements” of the periodic table.
• The Roman numbers I and VIII occur in two groups, group A and group B. In each group, the roman number represents the total number of outer electrons present in the atoms of the element that falls into that group.

The newer system numbers the groups from 1 to 18 from left to right. Group 1 is the alkali metals group, group 2 is the alkali earth metals group, and group 18 is the noble gases group, group 15 the nitrogen family, and so on.