what is the deinition to groups in chemistry?

Answer 1

If you referring to groups in periodic table then by looking at the table to you will see that elements are grouped in vertical columns. The grouping or family classification stems from the valance or by the number of electrons contained on the on the valance shell of a particular element..

The valance reflects the way the atom of an element interacts with other atoms of other elements. Every group has their peculiar behavioral characteristics and given relevant names such as the alkali metals, alkaline earth metals, transition metals, halogens and noble gases.