What two ingredients make a sherbet fizzy?

The two key ingredients that make a sherbet fizzy are sodium bicarbonate (also known as baking soda) and citric acid.

Here's how it works:

* Sodium bicarbonate is a base.

* Citric acid is an acid.

When these two ingredients come into contact with each other, they react to produce carbon dioxide gas. This gas gets trapped in the sherbet, creating the characteristic fizzy sensation.

The addition of water (from saliva) helps to accelerate the reaction, making the fizz even more pronounced.