( It ( ( ( 's ( like ( ( ( a ( subatomic particle ) ) , ) ( an electron ) ) ) ) perhaps ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ 's) (PP (IN like) (NP (NP (DT a) (JJ subatomic) (NN particle)) (, ,) (NP (DT an) (NN electron)))) (ADVP (RB perhaps))) (. .)))
It's like a subatomic particle, an electron perhaps.
(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)))))))) (. .)))