How can the ph scale tell you if a substance is an acid a base or neutral?

The Ph  scale  can tell you if a substance  is an acid a base or neutral  by

  a Ph scale  runs from a Ph of 1-14. if a substance has  a Ph less than 7 (Ph<7)  the substance is said to be a an acid

if  a substance has a ph greater than  7 (Ph>7) the substance is said to be a base

if a  substance has a Ph equal to 7(Ph=7)  the substance is said to be neutral

Naoh + hbr -> nabr (salt) + h2o ca (oh)2 + 2hbr - - - > ca (br)2 + 2h2o