Question

The atomic radii of the three elements A, B and C of a periodic table are 186pm,104pm and 143pm respectively. Giving reason arrange these elements in the increasing order of atomic numbers in the period.

Answer 1

B<C<A ,   this is becoz more the atomic mass more valence electrons/ electron shells more the atomic no. of elements except few exceptions

Answer 2

Answer:

the order will be B-C-A

Explanation:

as we move from left to right on the periodic table the atomic size/atomic radii decreses . It is because the eletronegativity [tendency to gain electrons] increases as we move from left to right.

I hope this will help. Please let me know if I am wrong.

Thank you.