(a) What do you understand by 'Periodic Table'.

(b) A part of the Periodic table is given below with the symbols of some elements. Write the symbols of the missing elements.

Group → Period ↓	IA	IIA	IIIA	IVA	VA	VIA	VIIA	Zero
1	H							He
2	Li		B		N		F
3		Mg		Si		S		Ar
4	K	Ca	x	x	x	x	x	x

(a) Periodic Table is a systematic arrangement of elements in a tabular form arranged into rows ("periods") and columns ("groups"), for our convenient study.

(b)