When calcium metal is dropped in water, it reacts vigorously, producing hydrogen gas (H₂) and calcium hydroxide (Ca(OH)₂).

Here's the balanced chemical equation for the reaction:

Ca (s) + 2H₂O (l) → Ca(OH)₂ (aq) + H₂ (g)

You'll observe the following:

* Fizzing and bubbling: This is due to the hydrogen gas being released.

* Heat generation: The reaction is exothermic, meaning it releases heat.

* Formation of a white precipitate: This is calcium hydroxide.

Caution: This reaction is quite vigorous, and the heat generated can be significant. It's best to perform this experiment with proper safety precautions in a controlled environment.