What do the groups in the periodic table mean?

Answer 1

The group number, in addition to designating the group of a column, also gives the number of valence electrons in an atom in that group. For example, with a group number of one, lithium, sodium, potassium, and the other alkalis all have one valance electron. Note that some periodic tables use a different format, and the number of valence electrons in groups after the transition metals is the group number minus 10.

Answer 2

Depends on what version you are looking at. The integers going from 1 to around 100 are the atomic numbers of the elements and these are the numbers of protons (= numbers of electrons) in the atom. Numbers which run from 1 to around 250 and are integers are the atomic weights of isotopes, and numbers which are not integers are atomic weights of elements found in nature, which are mixtures of isiotopes.

Answer 3

The modern numbering system of the groups is meaningless. The groups are just numbered 1-18 from left to right across the Periodic Table.

In the older American numbering system which you still see on some old charts, the representative element groups were numbered IA - VIIIA. These indicated the number of valence electrons the elements in those groups have.

Answer 4

Group numbers represent valance electrons.

Answer 5

groups are vertical columns that have elements with the same physical and chemical properties, another name for a family

Answer 6

They help the organization of the periodic table.