Here's why:

* Dissociation: Strong acids dissociate almost completely in water, meaning they break apart into hydrogen ions (H+) and anions.

* 99% Dissociation: The high percentage of dissociation (99%) indicates a strong tendency to release hydrogen ions, a hallmark of strong acids.

Examples of strong acids include:

* Hydrochloric acid (HCl): This is one of the most common strong acids, found in our stomachs.

* Sulfuric acid (H₂SO₄): Used in car batteries and many industrial processes.

* Nitric acid (HNO₃): Used in the production of fertilizers and explosives.

Important Note: While the information provided strongly suggests a strong acid, it's impossible to pinpoint the exact compound without further details like the anion produced or its molecular formula.