Question

Two elements 'P' and 'Q' belong to the same period of the modern periodic table and are in Group -1 and Group -2 respectively. Compare their following characteristics in tabular form : 

(i) The number of electrons in their atoms 

(ii) The sizes of their atoms 

(iii) Their metallic characters 

(iv) Their tendencies to lose electrons 

(v) The formula of their oxides 

(vi) The formula of their chlorides

Answer 1

Sr. No.	Property	P	o
(i)	No. of electrons in the atom	3 11 19	4 12 20 (any one pair)
(ii)	Size of the atom	Bigger	Smaller
(iii)	Metallic character	More metallic	Less metallic
(iv)	Tendency to lose electrons	More	More
(v)	Formula of oxides	P2O	QO
(vi)	Formula of chlorides	PCI	QCl2

Note: For parts (v) and (vi) examples using symbols of elements may also be accepted.

Detailed Answer:

(i) P has 1 valence electron, Q has 2 valence electrons.

(ii) 'P' is bigger than 'Q'.

(iii) 'P' is more metallic than 'Q'.

(iv) 'P' has more tendency to lose electrons than 'Q'.

(v) P₂O and QO are formulae of their oxides.

(vi) P Cl and Q Cl₂ are formulae of their chlorides.