( ( Since ( ( most ( metal ( ion indicators ) ) ) ( ( are also ) ( acid-base indicators ) ) ) ) ( , ( they ( ( have ( different colors ) ) ( at ( ( different values ) ( of pH. ) ) ) ) ) ) )
(ROOT (S (SBAR (IN Since) (S (NP (JJS most) (NN metal) (NN ion) (NNS indicators)) (VP (VBP are) (ADVP (RB also)) (NP (JJ acid-base) (NNS indicators))))) (, ,) (NP (PRP they)) (VP (VBP have) (NP (JJ different) (NNS colors)) (PP (IN at) (NP (NP (JJ different) (NNS values)) (PP (IN of) (NP (NN pH.))))))))
Since most metal ion indicators are also acid-base indicators, they have different colors at different values of pH.
(ROOT (S (SBAR (IN If) (S (NP (DT a) (NN substance)) (VP (VBZ has) (NP (DT a) (NN ph) (NN value)) (NP (QP (JJR greater) (IN than) (CD 7)))))) (, ,) (NP (DT that)) (VP (VBZ indicates) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ is) (NP (NN base)))))) (. .)))
If a substance has a ph value greater than 7,that indicates that it is base.