Chemistry

Study of matter, its properties, and the changes it undergoes.

Basic Concepts

Physical and Chemical Properties

Exploring How Matter Behaves

Every type of matter has unique properties that help us identify and describe it. These properties can be physical or chemical.

Physical Properties

Physical properties are characteristics you can observe or measure without changing what the substance is. Some common physical properties include:

  • Color
  • Odor
  • Density
  • Melting and boiling points
  • Hardness

You can measure the melting point of ice or the color of gold without changing their identities.

Chemical Properties

Chemical properties describe how a substance can change into a new substance. These are only observed when a chemical reaction happens. Examples are:

  • Flammability (can it burn?)
  • Reactivity with acids or bases
  • Ability to rust (like iron)

If you burn wood, it becomes ash and gases—showing a chemical property.

Why Are Properties Important?

Knowing the properties of matter helps us use substances safely and effectively.

Examples

  • Melting ice is a physical change because it is still water, just in a different form.

  • Burning paper is a chemical change because it turns into ash and gases.

In a Nutshell

Physical properties can be observed without changing the substance, while chemical properties describe how it can change.