Place the following elements in order of decreasing atomic size:

a. lead

b. phosphorus

c. oxygen

d. cesium

e. barium

f. silicon.

Rank below mention elements from largest to smallest.

a. Cs

b. O

c. P

d. Si

e. Ba

f. Pb

Caesium (Cs) > Barium (Ba) > Lead (Pb) > Silicon (Si) > Phosphorus (P) > Oxygen (O)

Explanation:

Before proceeding, we need to understand the trend of atomic sized.

In the periodic table, atomic size generally decreases form left to right in a period. It increases down the group.

Having known this, the order of the elements is thus given as;

Caesium (Cs) > Barium (Ba) > Lead (Pb) > Silicon (Si) > Phosphorus (P) > Oxygen (O)