Question

The elements of the second period of the Periodic Table are given below: Li Be B C N O F

(a) Give reason to explain why atomic radii decrease from Li to F.

(b) Identify the most

(i) metallic and

(ii) non-metallic element.

Answer 1

(a) Atomic radii decreases in moving from left to right along a period due to increase in nuclear charge which pull the electrons closer to the nucleus and reduces the size of the atom.

(b) Li: most metallic F: most non-metallic

(c) Valency first increases from +1 to 4 and then decreases from -3 to 0.