When zinc is put in hydrochloric acid, a chemical reaction takes place. The zinc metal reacts with the hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). The reaction can be represented by the following equation:

Zn + 2HCl → ZnCl2 + H2

During the reaction, the zinc atoms lose electrons to the hydrogen ions (H+) in the hydrochloric acid, resulting in the formation of zinc ions (Zn2+) and hydrogen gas. The hydrogen gas produced is released as bubbles, causing effervescence and fizzing.

This reaction is an example of a single-displacement reaction, where one element (zinc) replaces another element (hydrogen) in a compound (hydrochloric acid). The reactivity of zinc with hydrochloric acid is relatively high, and the reaction proceeds at a moderate rate at room temperature.

It's important to note that this reaction should be carried out with caution. Hydrochloric acid is a corrosive substance and can cause skin burns and eye damage. Proper safety precautions, such as wearing gloves and eye protection, should be taken when working with hydrochloric acid.