aine vähim osake, mis osaleb keemilises reaktsioonis (vrd molekul)
Hea teada
Iga aatom koosneb suhteliselt tihedast tuumast selles paiknevate positiivselt laetud prootonite ja neutraalsete osakeste - neutronitega ning väljaspool tuuma paiknevatest prootonite arvuga võrdse arvuga elektronidest.
the smallest particle of an element which can take place in a chemical reaction (compare: molecule)
Hea teada
Each atom consists of a relatively dense nucleus composed of positively charged protons and neutral particles (neutrons); there is an equal number of electrons outside the nucleus to balance this charge.
