To observe what happened when yeast and sugar is added to warm water.
Yeast,Sugar,Warm water, Glass & Spoon.
Add 1/2 spoonful of yeast and 1 spoonful of sugar to ¼ cup of warm water. Let it sit for few minutes.
The warm water, yeast and sugar together caused foaming due to fermentation. Bubbles come out as the yeast produces carbondioxide.Its a chemical change.