( Electrons ( ( are ( ( subatomic particles ) ( that ( orbit ( ( the nucleus ) ( of ( an atom ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Electrons)) (VP (VBP are) (NP (NP (JJ subatomic) (NNS particles)) (SBAR (WHNP (WDT that)) (S (VP (VB orbit) (NP (NP (DT the) (NN nucleus)) (PP (IN of) (NP (DT an) (NN atom))))))))) (. .)))
Electrons are subatomic particles that orbit 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)))))))) (. .)))