The sandwich example relates to the Law of Conservation of Matter for Chemical Equations. Matter cannot be created nor destroyed. This is why there must be the same number of atoms on the reactant side as on the product side.

Answer 1

In the sandwich example, imagine you have a sandwich made with two slices of bread (representing the reactants) and filling like lettuce, tomato, and cheese (representing the products). According to the Law of Conservation of Matter, the total number of atoms in the reactants (bread slices and filling) must be equal to the total number of atoms in the products.

If you were to take apart the sandwich and count the number of atoms of each element (e.g. carbon, oxygen, nitrogen) in the bread and filling, you would find that they remain the same before and after making the sandwich. This demonstrates that matter cannot be created or destroyed in a chemical reaction, only rearranged.

By applying this concept to chemical equations, scientists and chemists can predict the amount of reactants needed and products formed in a chemical reaction, ensuring that the Law of Conservation of Matter is upheld.