Question

which one is larger in size?
po
se
s
o

Explanation:

Step1: Recall atomic - size trend

Atomic size increases down a group and decreases across a period in the periodic table.

Step2: Locate elements

Po (Polonium) is in Group 16 and Period 6. Se (Selenium) is in Group 16 and Period 4. S (Sulfur) is in Group 16 and Period 3. O (Oxygen) is in Group 16 and Period 2.

Step3: Compare sizes

Since all are in the same group (Group 16), the element with the highest period number will have the largest atomic size. Po is in the highest period (Period 6) among them.

Answer:

Po