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)

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i