Answer:
A. begin with hydrogen; pair a metal with a hydroxide ion
Explanation:
Acid can be distinguished from base on the basis of formulas in such a way that acid formula start with hydrogen.
For example:
Hydrochloric acid is strong acid. Its formula is HCl.
It start with hydrogen
Sulfuric acid is acid. Its formula is H₂SO₄
it is also start with hydrogen.
Base:
Base is distinguish from acid in such a way that in base formula metal is pair with hydroxide ion.
For example:
Sodium hydroxide is base. Its formula is NaOH.
sodium is metal while OH is hydroxide ion.
Potassium hydroxide is base. its formula is KOH.
potassium is metal and OH is hydroxide ion.