Pure Substances and Mixtures – What Are They?

What is matter?

• Anything that takes up space and has mass

• Is your paper matter?

YES!!

The Particle Theory

• In 400 B.C.E. Democritus stated that:

ALL matter (solids, liquids and gases) is made up of tiny particles.

THE FIRST PRINCIPLE!!

The Particle Theory of Matter1. All matter is composed of very small particles 2. All the particles of matter are in constant

motion

3. All particles of one substance are identical4. Temperature affects the speed at which

particles move5. Particles attract each other

Vocabulary!Pure Substance – matter consisting of only one type of particle (e.g. distilled water, refined sugar)

Mixture – matter consisting of more than one type of particle (e.g. air, tap water, granola). Mixtures can be divided into two categories: mechanical mixtures and solutions.

Mechanical Mixture – a mixture where individual particles can be identified (e.g. granola, concrete). Mechanical mixtures can be homogenous or heterogeneous.

Homogeneous Mixture – a mixture where particles of each component substance are evenly dispersed

Heterogeneous Mixture – a mixture where particles of each component substance are not evenly dispersed

Solution – a mixture where individual particles are interspersed homogeneously. Individual particles cannot be identified (e.g. air, tap water)

In your science binder, answer the following question:

If I spray an air freshener on one side of the classroom, how do you

think you are able to smell it on the other side of the classroom?