( ( These entities ) ( ( can ( be ( ( ( ( ( ( ( ( ( ( ( molecules , ) atoms ) , ) ions ) , ) electrons ) or ) ( other ( subatomic particles ) ) ) , ) or ) ( groups ( of particles ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS entities)) (VP (MD can) (VP (VB be) (NP (NP (NP (NNS molecules)) (, ,) (NP (NNS atoms)) (, ,) (NP (NNS ions)) (, ,) (NP (NNS electrons)) (CC or) (NP (JJ other) (JJ subatomic) (NNS particles))) (, ,) (CC or) (NP (NP (NNS groups)) (PP (IN of) (NP (NNS particles))))))) (. .)))
These entities can be molecules, atoms, ions, electrons or other subatomic particles, or groups of particles.
(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)))))))) (. .)))