Question

what is an indicator for chemistry? How is this for a definition? Thanks

A susbtance that changes colour when added to a base or an acid. The colour it changes to will depend on which it is added to.
bobpursley
it doesn't have to be an acid or base. Most of the medical test strips now (cancer, pregnancy, blood sugar level) use biochemical reactions to make a spot of color to indicate a change.

Emmzy
They are chemicals used in reaction so as to obtain a sharp endpoint