Questions: Which of the atoms listed below has the largest atomic size? A) Cl B)। C) P D) Sb E) Se

Solution Steps

Atomic size, or atomic radius, generally increases as you move down a group in the periodic table and decreases as you move across a period from left to right. This is due to the addition of electron shells as you move down a group and the increase in nuclear charge as you move across a period.

The elements listed are:

• Cl (Chlorine)
• P (Phosphorus)
• Sb (Antimony)
• Se (Selenium)

• Cl (Chlorine) is in Group 17, Period 3.
• P (Phosphorus) is in Group 15, Period 3.
• Sb (Antimony) is in Group 15, Period 5.
• Se (Selenium) is in Group 16, Period 4.

Since atomic size increases down a group and decreases across a period:

• Sb (Antimony) is in Period 5, which is lower than the other elements listed, indicating it has more electron shells and thus a larger atomic size.

Final Answer