Final answer:
In each presented pair, the element with the larger atomic radius is C (carbon), Ca (calcium), Al (aluminum), and P (phosphorus) respectively, based on their positions in the periodic table which reflects periodic trends of atomic size.
Step-by-step explanation:
The student is asking to circle the element with the larger atomic radius in each given pair. The atomic radius generally increases as we move down a group in the periodic table because additional electron shells are added, and it decreases across a period from left to right due to the increased positive charge in the nucleus pulling electrons closer. Here are the larger atomic radii in the given pairs:
- A) C (carbon) - Carbon has a larger atomic radius than nitrogen because it is to the left in the same period.
- B) Ca (calcium) - Calcium has a larger atomic radius than magnesium; it is below magnesium in the same group.
- C) Al (aluminum) - Aluminum has a larger atomic radius than chlorine; it is to the left of chlorine in the same period.
- D) P (phosphorus) - Phosphorus has a larger atomic radius than oxygen because it is below oxygen in the same group.
The subject of this question is Chemistry, specifically, periodic trends regarding atomic radius within the periodic table.