Strong acid
In chemistry, a strong acid is an acid which ionizes (splits) completely in a solution of water. It always loses a proton (A H+) when put in water. A weak acid does not always lose a proton, though; It can lose its proton, but not all the time. They also have a very low pH, usually between 1 and 3. Many strong acids have a negative pKa value, which means they are very strong.