how many groups in periodic table

There are 18 groups in the periodic table, numbered from 1 to 18. These groups are the vertical columns of the periodic table, and elements in the same group have similar chemical properties due to their outer electron configurations. The 14 f-block columns between groups 2 and 3 are not numbered as groups. The 18 groups include categories such as alkali metals (Group 1), alkaline earth metals (Group 2), halogens (Group 17), and noble gases (Group 18) among others.