Introduction to Matter

Matter is any substance that occupies space and has its own mass. Everything in the world, including water, tables, pens, pencils, drinking glasses, and human beings, occupies space and possesses mass.

Demonstrating that air has mass

When water is emptied from a glass, air immediately moves in and takes over that space. Air is matter because it occupies space and possesses mass, which can be proved through a balance experiment. A string is tied to the middle of a stick, with a blown-up balloon attached to one end and an empty balloon tied to the opposite end. The stick tilts downward on the side holding the blown-up balloon, proving that the trapped air inside has mass.

How atoms form molecules and compounds

Matter is built from tiny particles called atoms. If a piece of cloth is cut into two pieces, then four pieces, and broken down continuously until it cannot be split anymore, it reaches an indivisible particle known as an atom. Each atom contains protons, neutrons, and electrons inside it. When individual atoms combine, they form a molecule, and molecules combine through a chemical reaction to form a compound. For example, water is a compound with the molecular formula H2O, created when two hydrogen atoms combine with one oxygen atom.

The three states of matter

Matter exists in three different states: solid, liquid, and gas. The specific state of a substance is determined by the distance between its tiny particles.

• In a solid state, such as a piece of iron, the distance between the particles is very small.
• In a liquid state, such as water, the distance between the particles is greater than in a solid.
• In a gaseous state, such as the air found in the atmosphere, the gap between the particles is very large.