Asolution that is a 4 on the ph scale is a a. weak acid b. strong acid c. weak base d. strong base

A solution that is a 4 on the pH scale is a (a) weak acid.

The pH scale is a universal measure of how much acidic or basic any substance is. The scale of pH ranges from 0 to 14 with 7 in middle being neutral i.e. neither acidic nor basic. Substances with pH less than 7 are considered to be acidic and more than 7 are considered to be basic. Strong acids have pH less than weak acid while strong bases have higher pH than weak bases.

Substances or solutions that have pH 0-3 are highly acidic, 4-6 are weakly acidic and pH of 7 is neutral solution while pH of 8-11 are weakly basic and 12-14 are highly basic.

the answer is "a.) well–developed vascular system."

explanation: