( ( On ( this scale ) ) ( , ( ( ( pH values ) ( of ( less ( than 7 ) ) ) ) ( ( indicate ( ( ( an acid ) , ) ( while ( ( those ( greater ( than 7 ) ) ) ( indicate ( ( a base ) ( -LRB- ( alkaline -RRB- ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN On) (NP (DT this) (NN scale))) (, ,) (NP (NP (NN pH) (NNS values)) (PP (IN of) (NP (QP (JJR less) (IN than) (CD 7))))) (VP (VBP indicate) (NP (NP (DT an) (NN acid)) (, ,) (SBAR (IN while) (S (NP (DT those) (QP (JJR greater) (IN than) (CD 7))) (VP (VBP indicate) (NP (NP (DT a) (NN base)) (PRN (-LRB- -LRB-) (NP (NN alkaline)) (-RRB- -RRB-)))))))) (. .)))
On this scale, pH values of less than 7 indicate an acid, while those greater than 7 indicate a base (alkaline).
(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.