Question

in what units are atomic radii typically measured? nanometers picometers meters angstroms why does atomic radius generally increase from top to bottom within a group? more principal energy levels are introduced nuclear charge decreases more protons are added electron repulsion becomes dominant

Explanation:

Atomic radii are typically measured in picometers. Angstroms are also used where 1 Å = 100 pm. Nanometers are too large a unit for typical atomic - scale measurements, and meters are far too large. As you move down a group in the periodic table, more principal energy levels are introduced. Each new energy level is farther from the nucleus, causing the atomic radius to increase. The nuclear charge does not decrease as you move down a group; in fact, it increases with the addition of more protons. Electron - electron repulsion is not the main factor in the increase of atomic radius down a group.

Answer:

1. Picometers
2. More principal energy levels are introduced