Question

Define periodic table and discuss its importance also.

Answer 1

• The arrangement of elements in rows and columns according to their atomic number, physical and chemical properties is called periodic table.
• It was difficult to study properties of all 118 elements, this systematic arrangement of elements make it simpler.
• The elements are arranged in increasing order of their atomic numbers in horizontal rows, which are called periods.
• The elements with similar properties fall together in vertical groups, which are called groups.
• There are 7 periods and 18 groups in a periodic table.
• The table can be used to guess the properties of elements that haven't been discovered yet.