Question

The elements of the third period of the Periodic Table are given below:

(a) Which atom is bigger, Na or Mg? Why?
(b) Identify the most (i) metallic and (ii) non-metallic element in Period 3.
(c) Which is more non-metallic, S or Cl?
(d) Which has higher atomic mass, A1 or​

Answer 1

Answer:

It is due to increased nuclear charge because of which force of attraction between the nucleus and valence electrons increases therefore atomic size decreases, so Na is bigger in size than Mg

Answer 2

Answer:

A) Na

B) Na most metallic, Ar most non-metallic

C) Cl  

Explanation:

A) As we move from left to right in the periodic table the effective nuclear charge increases, as the effective nuclear charge inc.  the atomic radii decreases.

So that's why Na has a bigger size than Mg.

B) In the periodic table as we move from left to right te metallic character decreases and the non-metallic character increases.

so in the 3rd period, Na is the most metallic and Ar is the most non-metallic element.

C) In S and Cl element Cl is more non-metallic