molecule

ace, dab, dash, driblet, drop, fraction, haet [chiefly Scottish], halfpenny, ha'penny, iota, jot, kenning [chiefly Scottish], lick, minim, mite, modicum, nutshell, ounce, pinch, shred, smatter, smidgen (also smidgeon), spot, strain, streak, suspicion, taste, touch, trace, whisper, whit

bite, mouthful, nibble, tidbit (also titbit)

fragment, part, portion, section

chip, flake, shard, shiver, sliver, splinter

clipping, paring, shaving

smithereens