Everything you see, breathe, drink, and sit on is matter. Matter is anything that has mass and takes up space. It can be a solid like a rock, a liquid like juice, or a gas like oxygen. Even substances that are invisible, such as the air inside a balloon, are considered matter. All matter is made of tiny particles called atoms and molecules. ^[1-4]

What Is the Law of Conservation of Matter

The law of conservation of matter, or law of conservation of mass, is a scientific rule that says ^[1-4]

 Matter cannot be created or destroyed

This means the total amount of matter stays the same, even when it changes form. It may look different after a change, but all the tiny particles are still there. They just rearrange or move to new places.

The law of conservation of matter was discovered by French chemist Antoine Lavoisier in 1789.

How Does the Law Work in Real Life

Let us understand this law through the changes matter can go through. ^[1-5]

Physical Changes: Matter Looks Different, But Stays the Same

A physical change is when matter changes its shape, size, or state (like solid to liquid), but it is still the same substance. For example:

• Ice melting into water
• Water boiling into steam
• Cutting a piece of paper into smaller pieces
• Breaking a glass bottle
• Dissolving sugar in water
• Freezing juice to make popsicles

None of these changes result in the creation of new substances.

Chemical Changes: New Substances Are Made

A chemical change is when matter changes into an entirely new substance. For example:

• Iron turning to rust
• Baking soda reacting with vinegar to make bubbles
• Burning a candle
• Cooking an egg
• Wood burning to form ash and smoke
• Milk turning sour

Even though new substances form, the total amount of matter is not lost. The atoms are just rearranged in different ways. As long as nothing leaves or enters the system, the total matter stays unchanged.

Everyday Examples of Conservation of Matter ^[1-5]

• Baking bread – Dough becomes bread, but all the matter is still there in a new form.
• Rusting iron – Iron reacts with oxygen to form rust, but the atoms are not lost.
• Shaking a sealed soda bottle – Bubbles form, but all matter stays inside.
• Boiling water in a closed pot – Water turns to steam, but nothing escapes.
• Burning a candle in a jar – Wax and wick become gases and ash, but the total matter remains.

Why Is The Conservation of Matter Important

The law of conservation of matter helps us understand what happens during chemical reactions. It shows that the atoms are still there, just in new forms. In high school, students use this law to balance chemical equations by making sure the number of atoms is the same on both sides. ^[1-5]

In the real world, this law is useful for:

• Cooking recipes
• Creating eco-friendly products
• Solving engineering problems

It is a simple but powerful idea that helps explain how the world works at the smallest level.