Classification of Matter

Physical And Chemical Properties

Section 1: The Basics

Atoms and Molecules

Every piece of matter in the world is made up of atoms. Every thing you own, every meal you've eaten, even the air that you breathe is made up of
atoms. Every atom belongs to an element - such as oxygen, carbon, iron, or gold. Of course, not everything can be made completely of a certain
element. When two or more atoms bond together to create a single particle, it's called a molecule. Most things, aside from pure substances, are
made up of molecules. For example, Water is made up of two elements: hydrogen and oxygen.

Classification of Matter

When a substance is made up of one element and that element only, the substance is referred to as a pure substance, or just an element. When
a substance is made up of molecules consisting of several different elements bonded together at the atomic level, that substance is a compound.
And when a substance is made up of multiple atoms or molecules mixed together but not bonded at the atomic level, that substance is a mixture.

Characteristics of Matter

The three most common states of matter are solid, liquid, and gas.

Solids have a definite shape, and also have a definite volume that can't be compressed.

Liquids have no definite shape, instead taking the shape of their container. However, like solids, they can't be compressed.

Gases have no definite shape at all, and they also can be compressed to any given volume.

Physical And Chemical Changes

A physical change involves a substance undergoing some sort of physical process that doesn't actually change it's chemical makeup. For example,
water freezing into ice would be considered a physical change. It's still made up of H2O, but it's in a different physical form. On the contrary,
a chemical change is when a substance's chemical makeup is altered. For example, when the iron on the outside of a nail turns to iron oxide - the
nail is still solid, but is now irreversably rusted.

This concludes the audio cast on classification of matter.