( ( ( ( ( ( The collisions ) ( exhibited ( by ( gas particles ) ) ) ) ( are ( completely elastic ) ) ) ; ) ( ( when ( ( two molecules ) collide ) ) ( , ( ( total ( kinetic energy ) ) ( is conserved ) ) ) ) ) . )
(ROOT (S (S (NP (NP (DT The) (NNS collisions)) (VP (VBN exhibited) (PP (IN by) (NP (NN gas) (NNS particles))))) (VP (VBP are) (ADJP (RB completely) (JJ elastic)))) (: ;) (S (SBAR (WHADVP (WRB when)) (FRAG (ADJP (NP (CD two) (NNS molecules)) (JJ collide)))) (, ,) (NP (JJ total) (JJ kinetic) (NN energy)) (VP (VBZ is) (VP (VBN conserved)))) (. .)))
The collisions exhibited by gas particles are completely elastic; when two molecules collide, total kinetic energy is conserved.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN gas) (NNS particles)) (VP (VBP collide)))) (, ,) (NP (DT these) (NNS collisions)) (VP (VBP are) (VP (VBN considered) (S (ADJP (JJ elastic))))) (. .)))