Sodium bicarbonate, more commonly called baking soda, is an ingredient used in baked goods like biscuits and muffins to help make them light and fluffy. Baking soda is also great for putting out a grease fire or creating a homemade volcano!
If you're a baker, you've used baking soda — it's the fine white powdery ingredient that often comes in a box. Baking soda is an effective leavening agent, helping cakes and cookies rise while they bake, through a chemical reaction with acids like buttermilk or lemon juice. In the U.K., baking soda is called bicarbonate of soda, which is closer to its scientific name, sodium bicarbonate; it's also known by the chemical formula NaHCO3.