Question

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

Answer 1

A C B as in a period atomic size decreases
because of increase in nuclear charge.

Answer 2

order is 186, 143, 104. because elements at the beginning of the periodic table have larger atomic radii