I can state the law of conservation of matter. I can identify reactants and products in a chemical reaction. I can explain how and why matter is conserved. I can through scientific investigations, demonstrate the law of conservation of matter. I can read a basic chemical equation.
Although energy cannot be created or destroyed, it can be transferred or transformed.
For instance, H2O is a chemical reaction between Hydrogen and oxygen.
For the standard, Nature of Matter: S8P1, Obtain, evaluate, and communicate information about the structure and properties of matter.
The law of conservation of matter is that energy cannot be created or be destroyed.
Reactants are the starting materials of a chemical reaction, and products is the result of that reaction.