Question

The atomic radii of the element of second period are given below:

Second period elements	B	Be	O	N	Li	F	C
Atomic Radii (pm)	88	111	66	74	152	64	77

(i) Arrange these elements in decreasing order of their atomic radii.

(ii) Are the elements now arranged in the pattern of a period in the periodic table?

(iii) Name the element which has the (a) largest and (b) smallest atomic number.

(iv) From the above data, infer how the atomic size or atomic radius of the elements changes as we go from left to right in a period.

(v) Name one metal, one non-metal and a metalloid out of these elements.

(vi) Why does atomic radius decreases as we move from left to right in a period?

Answer 1

(i) Li Be B C N O F
152 111 88 77 74 66 64

(ii) Yes, the elements are now arranged in the pattern of a period of periodic table.

(iii) (a) Li has the smallest atomic number.
(b) F has the largest atomic number.

(iv) Atomic radius decreases on moving from left to right in a period of the periodic table.

(v) Metal: Li, Non-metal: C, Metalloid : B

(vi) Force of attraction for the outermost electrons increases because of increased nuclear charge.