Question

(a) How does the atomic radius changes as you go
(i) from left to right in a period?
(ii) down a group in the periodic table?
(b) Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the Modern Periodic Table do these two elements belong? What type of bond will be formed between them and why?

Answer 1

Explanation:

1) when when we go left to right in a period atomic radius goes on decreasing.

2)when we go down a group in a periodic table the atomic radius goes on increasing

3) electronic configuration

x= 12 = Mg = ( 2,8,2)

y= 16= S= (2,8,6)

elements magnesium and sulphur belongs to 3rd period

ionic Bond can be formed between magnesium and sulphur

Answer 2

Periodic Table

Explanation:

a) Atomic radius.

(i) When when move from left to right in a period, the atomic radius of the elements decreases.

(ii) When we move from up to down a group in the periodic table, the atomic radius increases.

b)  

x = atomic number 12. We infer that the element is Magnesium (Mg). Electronic configuration: 2, 8, 2.

y = atomic number 16. We infer that the element is Sulphur (S). Electronic configuration:  2, 8, 6.

Mg tends to lose two electrons while Sulphur tends to attract two electrons to form the octet. So the compound formed by the two elements will have ionic bonds.