atom (n.)
- ace
- acid
- acidity
- agent
- air
- alkali
- alkalinity
- anion
- antacid
- base
- bit
- cation
- chemical
- component
- compound
- constituent
- copolymer
- dab
- dash
- dimer
- dole
- dot
- dram
- dribble
- driblet
- dwarf
- dyad
- earth
- electron
- element
- fabric
- farthing
- fire
- fleck
- flyspeck
- fragment
- gobbet
- grain
- granule
- groat
- hair
- handful
- heptad
- hexad
- hyle
- hypostasis
- ion
- iota
- isobar
- isomer
- jot
- little
- lota
- macromolecule
- material
- materiality
- matter
- medium
- meson
- minim
- minimum
- mite
- modicum
- molecule
- monad
- monomer
- mote
- nature
- nutshell
- octad
- one
- ounce
- oxyacid
- particle
- pebble
- pentad
- pinch
- pittance
- plenum
- point
- polymer
- proton
- quark
- radical
- reagent
- scruple
- shade
- shell
- smack
- smidgen
- soupcon
- speck
- spice
- spoonful
- spot
- stuff
- substance
- substratum
- suggestion
- suspicion
- tangible
- tetrad
- thimbleful
- tincture
- tinge
- tittle
- touch
- trace
- tracer
- triad
- trimer
- trivia
- unit
- water
- whit