Basic Concepts
In a nutshell: Physical properties can be observed without changing the substance, while chemical properties describe how it can change.
## 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.