( ( These ( intermediary atoms ) ) ( ( ( ( collide ( with ( the ( xenon ( gas atoms ) ) ) ) ) , ) ( polarizing ( ( the spin ) ( of ( their nuclei ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (JJ intermediary) (NNS atoms)) (VP (VBP collide) (PP (IN with) (NP (DT the) (JJ xenon) (NN gas) (NNS atoms))) (, ,) (S (VP (VBG polarizing) (NP (NP (DT the) (NN spin)) (PP (IN of) (NP (PRP$ their) (NNS nuclei))))))) (. .)))
These intermediary atoms collide with the xenon gas atoms, polarizing the spin of their nuclei.
(ROOT (S (PP (IN Within) (NP (DT a) (NN substance))) (, ,) (NP (NP (NNS atoms)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBP collide) (ADVP (RB frequently))) (CC and) (VP (VBP move) (ADVP (RB independently)) (PP (IN of) (NP (CD one) (DT another)))))))) (VP (VBP are) (ADJP (ADJP (RBS most) (JJ likely)) (PP (IN in) (NP (DT a) (NN gas)))))))