( ( When ( ( ( the volume ) ( of oxygen ) ) ( ( is chemically ) ( combined ( with ( ( the volume ) ( of hydrogen ) ) ) ) ) ) ) ( , ( ( the ( compounded mixture ) ) ( ( ( occupies ( ( exactly ( the ( same amount ) ) ) ( of space ) ) ) ( as ( ( the ( smaller volume ) ) ( of atoms ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (DT the) (NN volume)) (PP (IN of) (NP (NN oxygen)))) (VP (VBZ is) (ADVP (RB chemically)) (VP (VBN combined) (PP (IN with) (NP (NP (DT the) (NN volume)) (PP (IN of) (NP (NN hydrogen))))))))) (, ,) (NP (DT the) (VBN compounded) (NN mixture)) (VP (VBZ occupies) (NP (NP (RB exactly) (DT the) (JJ same) (NN amount)) (PP (IN of) (NP (NN space)))) (PP (IN as) (NP (NP (DT the) (JJR smaller) (NN volume)) (PP (IN of) (NP (NNS atoms)))))) (. .)))
When the volume of oxygen is chemically combined with the volume of hydrogen, the compounded mixture occupies exactly the same amount of space as the smaller volume of atoms.
(ROOT (S (NP (DT The) (NN term) (NN volume)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB describe) (S (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN space)))) (ADJP (VBN occupied) (PP (IN by) (NP (NP (DT a) (NN sample)) (PP (IN of) (NP (NN matter)))))))))))) (. .)))