Chemical Reactions MS-PS1-5

Atom

The smallest particle of an element. Atom. An atom is the basic building block of all matter, like tiny pieces that make up everything around us.

Coefficient

A number placed in front of a symbol or formula in a chemical equation. Coefficient. In chemistry, a coefficient tells you how many molecules or atoms of each substance are involved in a reaction.

Law of conservation of mass

States that mass cannot be created or destroyed in a chemical reaction. Law of Conservation of Mass. In a chemical reaction, the amount of stuff you start with is the same as the amount you end with, just rearranged.

Model

A representation of an object or system. Model. In Grade 7 NGSS, a model is a simplified way to show how something works or looks by using drawings, diagrams, or simulations.

Molecule

A group of atoms held together by bonds. Molecule. A molecule is like a tiny building block made of atoms that join together, forming everything around us.

Product

A new substance formed by a chemical reaction product. In a chemical reaction, a product is the new substance that is created when the original substances, called reactants, interact.

Reactant

A substance that is changed in a chemical reaction. Reactant. In simple terms, a reactant is a starting material in a chemical reaction that gets used up as it turns into products.