Final answer:
The atomic radius generally decreases across a period and increases down a group in the periodic table.
Step-by-step explanation:
The atomic radius is a measure of the size of an atom, specifically the distance from the nucleus to the outermost electron shell. In general, atomic radius decreases across a period and increases down a group in the periodic table. Using this information, we can determine which pairs of elements have the larger atomic radius.
From the given options:
a. Barium (Ba) or Bismuth (Bi): Bismuth (Bi) has a larger atomic radius than Barium (Ba).
b. Beryllium (Be) or Barium (Ba): Barium (Ba) has a larger atomic radius than Beryllium (Be).
c. Rubidium (Rb) or Chlorine (Cl): Rubidium (Rb) has a larger atomic radius than Chlorine (Cl).
d. Calcium (Ca) or Krypton (Kr): Calcium (Ca) has a larger atomic radius than Krypton (Kr).
e. Rubidium (Rb) or Iodine (I): Rubidium (Rb) has a larger atomic radius than Iodine (I).