Classification of Matter

What is matter?

• Anything that occupies space and has mass

What is matter made of?

• Substances: matter that is an element or a compound

So how do we classify matter:

- By the materials matter is made up of

- 4 states of matter

Example:

• How would you classify a

pencil?

- Wood

- Graphite

- Eraser

Break it down to the to its simpler parts!!!!

Elements

• The unit that makes up all matter are atoms– If all atoms of the sample of matter have the

same identity they are called elements (see periodic table of elements)

• Example: Oxygen

Compounds

• What happens when two or more elements come together?– They form a Compound

• Example: H20 – H is an element, O is an element, together they form

the compound water

How about table salt?

• Table salt is a compound:– NaCl

• Na is an element, Cl is an element– Together they form a compound

Mixtures

• What happens if you combine salt and water?

– When you combine two or more substances that can be separated by physical means you have a mixture!

• Salt can be separated from water by evaporation!!!

Back to the pencil!

• The pencil is a MIXTURE:– Wood (compound)– graphite (element)– Eraser (compound)

Solutions

• Salt water – mixture– Can you see the salt in the water?

• No• Homogenous Mixture –

– A material in which two or more substances are spread out evenly and cannot settle out when standing

Homogenous mixture = Solution

Heterogenous Mixtures

• A mixture in which different parts can be easily distinguished

– Example: Pencil, Peanut Butter and Jelly Sandwich

Categories of Heterogenous Mixtures

• Colloids – Heterogenous mixture that never settles– Example: Milk

– How can you tell it’s a colloid?• By the Tyndall Effect

– The scattering of light by the particles in the mixture

Suspension

• Some mixtures are neither solutions nor colloids

– They are known as a suspension• Is a heterogenous mixture containing a liquid in

which visible particles settle out when standing– A muddy river

» How is this different from a solution or colloid?

- Particles carried in suspension will settle out