The substance that starts the process of breaking chemical bonds or forming new bonds. It's one of the starting materials that participate in the transformation into different substances.

The new substance created after substances breakdown or form new bonds. It's what you end up with after the starting substances have undergone changes.  This new substance can be a compound (a completely different substance made of two or more things) or an element.

This describes how a substance behaves when it interacts with other substances or undergoes a chemical change. They show how a material can transform into new substances, like whether it rusts, burns, or reacts with other things.  

Examples:  Flammability, toxicity, corrosiveness, conductivity, etc.

How the substance behaves.

Characteristics of a substance that can be observed or measured without changing what the substance is. These characteristics include things like color, shape, size, texture, and how something feels or smells.

A chemical reaction that gives off heat or light. It releases energy outward, making things around it warmer.

A chemical reaction that absorbs heat from its surroundings. It feels cold when it takes in warmth from the air around it.

A substance that increases the rate of a chemical reaction.

A substance that decreases the rate of a chemical reaction.

The principle that states the total mass of substances before a chemical reaction equals the total mass after the reaction; mass is conserved.