Question

what is not a type of leavening agent

yeast

corn starch

baking soda

air

Explanation:

Leavening agents are substances that cause dough or batter to expand by releasing gas. Yeast ferments sugars to produce carbon dioxide. Baking soda reacts with acids to release carbon dioxide. Air can be incorporated into batters (e.g., whipped egg whites) to create lift. Corn starch, however, is a thickening agent (used to thicken sauces, puddings etc.) and not a leavening agent.

Answer:

Corn Starch