Question

The following diagram shows a part of the periodic table in which the elements are arranged according to their atomic numbers. (The letters given here are not the chemical symbols of the elements):

a 3	b 4		c 5	d 6	e 7	f 8	g 9	h 10
i 11	j 12		k 13	l 14	m 15	n 16	o 17	p 18

(i) Which element has a bigger atom, a or f?
(ii) Which element has a higher valency, k or o?
(iii) Which element is more metallic, i or k?
(iv) Which element is more non-metallic, d or g?
(v) Select a letter which represents a non-metal of valency 2.
(vi) Select a letter which represents a noble gas.

Answer 1

(a) As we move from left to right in a periodic table size of element decreases due to the increase in the number of electrons in the shell, they are pulled strongly towards the nucleus. Hence, the bigger atom is "a".

(b) Valency can be defined as the number of electrons available for bond formation.
Valency of k = 3
Valency of o = 1
Hence, "k" have higher valency.

(c) On movind left to right in a periodic table metallic character decreases.
On moving down the group metallic character increases.
So, "i" will be more metallic.

(d) On moving left to right in a periodic table non-metallic character increases.
On moving down the group non-metallic character decreases
So, "g" will be more metallic.

(e) Valency can be defined as the number of electrons available for bond formation.
Valency of f and n is 2.

(f) "h" and "p" represents noble gas.