( ( electron ( ( A ( small ( , ( indivisible particle ) ) ) ) ( that ( orbits ( ( the nucleus ) ( of ( an atom ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB electron) (NP (NP (DT A) (JJ small) (, ,) (JJ indivisible) (NN particle)) (SBAR (WHNP (WDT that)) (S (VP (VBZ orbits) (NP (NP (DT the) (NN nucleus)) (PP (IN of) (NP (DT an) (NN atom))))))))) (. .)))
electron A small, indivisible particle that orbits the nucleus of an atom.
(ROOT (S (NP (JJ Atomic) (NNS orbitals)) (VP (VBP are) (ADJP (VBN populated) (PP (IN with) (NP (NP (JJ subatomic) (NNS particles)) (VP (VBN known) (PP (IN as) (NP (NNS electrons)))))))) (. .)))