Which element in the second period of the periodic table has the largest atomic radius?

• A. Carbon (C)
• B. Lithium (Li)
• C. Beryllium (Be)
• D. Neon (Ne)

Answer: (B)

Verified step by step guidance

1. Recall that atomic radius generally decreases across a period from left to right on the periodic table due to increasing nuclear charge pulling electrons closer to the nucleus.
2. Identify the elements given in the problem and their positions in the second period: Lithium (Li) is group 1, Beryllium (Be) is group 2, Carbon (C) is group 14, and Neon (Ne) is group 18.
3. Understand that since all these elements are in the same period, the number of electron shells is the same, so the difference in atomic radius is mainly due to the effective nuclear charge.
4. Recognize that Lithium, being the furthest to the left in the period, has the smallest effective nuclear charge and thus the largest atomic radius among the options.
5. Conclude that Lithium (Li) has the largest atomic radius among the given elements in the second period.