Yield Sign: In a chemical equation, this is the arrow that separates reactants from products. It's like the equals sign in a math problem.
Conservation of Mass: This principle states that mass cannot be created or destroyed in a chemical reaction. So, if you start with 500g of ingredients (reactants), you'll end up with 500g of cookies and crumbs (products).
Endothermic Reaction: A chemical reaction that absorbs heat energy. Imagine ice melting into water - it takes in heat from its surroundings to do so.