the.com/atomic radius
How far an atom's electron cloud sprawls before it's someone else's problem.
means The typical distance from an atom's nucleus to the outer edge of its electron cloud, used to gauge how big an atom effectively is.
from From Greek 'atomos' ('uncuttable,' the old belief that atoms were matter's smallest, indivisible bits) plus Latin 'radius' ('spoke of a wheel, ray'), which drifted from literal spokes to any measure drawn outward from a center. Chemists borrowed that sense wholesale once they needed a word for the fuzzy boundary of an electron cloud — fittingly, the 'uncuttable' atom turned out to be mostly space, measured in spokes that don't quite end where you'd expect.
- direction, not size
- decreases left to right despite adding electrons
- why it shrinks
- more protons pull the cloud in tighter
- down a group
- grows as new electron shells stack on
- measurement catch
- impossible to pin exactly, electrons dont stop sharply