( ( ( The principle ) ( ( by which ) ( diffusion occurs ) ) ) ( ( dictates ( that ( ( ( a gas ) ( in ( high concentration ) ) ) ( will ( ( ( move ( to ( ( an area ) ( of ( ( relatively low ) concentration ) ) ) ) ) , ) ( until ( ( an equilibrium ) ( is reached ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN principle)) (SBAR (WHPP (IN by) (WHNP (WDT which))) (S (NP (NN diffusion)) (VP (VBZ occurs))))) (VP (VBZ dictates) (SBAR (IN that) (S (NP (NP (DT a) (NN gas)) (PP (IN in) (NP (JJ high) (NN concentration)))) (VP (MD will) (VP (VB move) (PP (TO to) (NP (NP (DT an) (NN area)) (PP (IN of) (NP (ADJP (RB relatively) (JJ low)) (NN concentration))))) (, ,) (SBAR (IN until) (S (NP (DT an) (NN equilibrium)) (VP (VBZ is) (VP (VBN reached)))))))))) (. .)))
The principle by which diffusion occurs dictates that a gas in high concentration will move to an area of relatively low concentration, until an equilibrium is reached.
(ROOT (S (NP (NNP Diffusion)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT the) (NN movement)) (PP (IN of) (NP (NP (NNS molecules)) (PP (IN from) (NP (NP (DT an) (NN area)) (PP (IN of) (NP (NP (JJ high) (NN concentration)) (PP (TO to) (NP (NP (DT an) (NN area)) (PP (IN of) (NP (JJ low) (NN concentration))))))))))))))) (. .)))