STARTING FROM SMALLEST TO BIGGEST
1 a. F , Br , k
b. Mg , Na , Cs
c. Ni , Fe , Os
Explanation: down the group , atomic radius increases . And across the group , atomic radius decreases . REFER PERIODIC TABLE TO SEE WHERE THE ELEMENTS ARE SITUATED
STARTING FROM BIGGEST TO SMALLEST
2 a. Ga , Br , Cl
b. Pb , Rn , Ne
c. Rb , Ca , C
Explanation: down the group , atomic radius increases . And across the group , atomic radius decreases . REFER PERIODIC TABLE TO SEE WHERE THE ELEMENTS ARE SITUATED