1. All the elements are arranged in the increasing order of their atomic number.
2. The horizontal rows are called periods. There are seven periods in the periodic table.
3.The elements are placed in periods based on the number of shells in their atoms.
4. Vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table.
5. Based on the physical and chemical properties of elements, they are grouped into various families.