a) What is meant by (i) a group, and (it) a period, in a periodic table? (b) How many periods and groups are there in the long form of periodic table? Give two examples each of (i) group 1 elements (ii) group 17 elements (iii) group 18 elements.

• Groups are the vertical columns in the periodic table

(i) A period is the horizontal rows of elements in the periodic table.

• There are seven periods and eighteen groups in the long form of [periodic
• (i) Group 1: Lithium and
  • Group 17: Fluorine and
  • Group 18: Neon and