( Diffusion ( ( is ( ( the ( passive movement ) ) ( of ( ( liquid ( or ( gas particles ) ) ) ( from ( ( an area ) ( of ( ( high concentration ) ( to ( ( an area ) ( of ( low concentration ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Diffusion)) (VP (VBZ is) (NP (NP (DT the) (JJ passive) (NN movement)) (PP (IN of) (NP (NP (NN liquid) (CC or) (NN gas) (NNS particles)) (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))))))))))))) (. .)))
Diffusion is the passive movement of liquid or gas particles from an area of high concentration to an area of low concentration.
(ROOT (S (NP (NNP Diffusion)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (DT a) (NN substance)) (ADVP (RB naturally)) (VP (VBZ moves) (PP (IN from) (NP (NP (DT an) (NN area)) (PP (IN of) (NP (NP (JJR higher)) (PP (TO to) (NP (JJR lower) (NN concentration)))))))))))) (. .)))
Diffusion is the process in which a substance naturally moves from an area of higher to lower concentration.