( ( Quantum mechanics ) ( ( is ( ( a way ) ( of ( ( describing interactions ) ( at ( ( ( ( ( ( ( ( ( ( very small ) scales ) ( of distance ) ) , ) ( ( ( ( the level ) ( of ( individual atoms ) ) ) , ) ( for instance ) ) ) , ) ( nuclei ( of atoms ) ) ) , ) or ) ( ( subatomic particles ) ( such ( as ( ( electrons or ) photons ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Quantum) (NNS mechanics)) (VP (VBZ is) (NP (NP (DT a) (NN way)) (PP (IN of) (S (VP (VBG describing) (NP (NNS interactions)) (PP (IN at) (NP (NP (NP (ADJP (RB very) (JJ small)) (NNS scales)) (PP (IN of) (NP (NN distance)))) (, ,) (NP (NP (DT the) (NN level)) (PP (IN of) (NP (JJ individual) (NNS atoms))) (, ,) (PP (IN for) (NP (NN instance)))) (, ,) (NP (NP (NNS nuclei)) (PP (IN of) (NP (NNS atoms)))) (, ,) (CC or) (NP (NP (JJ subatomic) (NNS particles)) (PP (JJ such) (IN as) (NP (NNS electrons) (CC or) (NNS photons))))))))))) (. .)))
Quantum mechanics is a way of describing interactions at very small scales of distance, the level of individual atoms, for instance, nuclei of atoms, or subatomic particles such as electrons or photons.
(ROOT (S (NP (NP (DT The) (JJ specialized) (NN study)) (PP (IN of) (NP (NP (DT the) (NN motion)) (PP (IN of) (NP (NP (NNS objects)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (ADJP (JJ atomic/subatomic) (PP (IN in) (NP (NN size)))))))))))) (VP (VBZ is) (VP (VBN called) (NP (NN quantum) (NNS mechanics)))) (. .)))
The specialized study of the motion of objects that are atomic/subatomic in size is called quantum mechanics.