Answer
The correct order of increasing size for the remaining groups of atoms is:
a. \( \mathrm{Be} < \mathrm{Na} < \mathrm{Rb} \)
b. \( \mathrm{Ne} < \mathrm{Se} < \mathrm{Sr} \)
c. \( \mathrm{O} < \mathrm{P} < \mathrm{Fe} \)
Work Step by Step
a. \( \mathrm{Rb}, \mathrm{Na}, \mathrm{Be} \)
The size of atoms generally increases as you move down a group in the periodic table. In this case, Be (beryllium) is at the top, Na (sodium) is in the middle, and Rb (rubidium) is at the bottom. Therefore, the order of increasing size is Be < Na < Rb.
b. \( \mathrm{Sr}, \mathrm{Se}, \mathrm{Ne} \)
The size of atoms generally increases as you move down a group in the periodic table. In this case, Ne (neon) is at the top, Se (selenium) is in the middle, and Sr (strontium) is at the bottom. Therefore, the order of increasing size is Ne < Se < Sr.
c. \( \mathrm{Fe}, \mathrm{P}, \mathrm{O} \)
The size of atoms generally increases as you move down a group in the periodic table. In this case, O (oxygen) is at the top, P (phosphorus) is in the middle, and Fe (iron) is at the bottom. Therefore, the order of increasing size is O < P < Fe.
Therefore, the correct order of increasing size for the remaining groups of atoms is:
a. \( \mathrm{Be} < \mathrm{Na} < \mathrm{Rb} \)
b. \( \mathrm{Ne} < \mathrm{Se} < \mathrm{Sr} \)
c. \( \mathrm{O} < \mathrm{P} < \mathrm{Fe} \)
