Chapter 3

Types of Matter

4 Types of Matter

Heterogeneous vs Homogeneous

• Heterogeneous matter has more than one phase (it is not uniform throughout).

• Homogeneous matter has only one phase (it is uniform throughout).

Make Your Choice

Heterogeneous or Homogeneous?

Ice Water

Is the matter heterogeneous? If yes.

It is a Heterogeneous Mixtures

What if the matter is not

heterogeneous?

It is then homogenous and is either an element, compound or solution.

Homogeneous Materials

Elements

Compounds

Solutions

If the matter is homogenous it may be a pure substance or a mixture.

• Ask…Can the composition vary?

Can the composition of water vary?

Can the Composition Vary?

Water?

If the composition can vary you have a homogeneous mixture (solution).

• All mixtures are made of 2 or more pure substances and can be separated by some physical method.

• Example: saltwater. The salt can be separated from the water by evaporating the water. However they are still the same substances with the same properties.

• If the mixture is homogeneous then the mixture is a solution.

Mixtures are a physical combination of substances (elements and compounds).

If the composition can vary you have a homogeneous mixture (solution).

• A homogeneous mixture is a solution.

Homogeneous Mixtures (Solutions)

An alloy is a homogeneous mixture of metals.

• Brass is an alloy of copper and zinc.

• The proportions of zinc and copper can be varied to create a range of brasses with varying properties.

Solutions

Solutions contain a solute and a solvent.

Solute and Solvent

• The solvent is the material that the solute is dissolved into. It is the major component of the solution.

• The solute is what gets dissolved into the solvent. It is any minor component(s).

Pure Substance

• In pure substances all the particles that make up the matter are the same, as a result the matter has constant properties and the composition cannot vary.

• Example: All pure water is a clear colorless substance that freezes at 0C and boils at 100C.

• Pure substances can be classified as: elements or compounds.

 

Elements

Bromine

Copper Neon

Arsenic

Elements

•Elements cannot be broken down into a simpler substance because they are made of only 1 kind of atom. (gold, oxygen, mercury).•Elements can be found on the periodic table. •Elements can exist as atoms or molecules.

Elements

• Combinations of two or more of the same chemical elements are not considered as compounds. For example, diatomic molecules like O2, H2, N2 or polyatomic molecules like P4 are not considered as compounds.

Compounds

Nitrogen dioxide (NO2) Sodium chloride (NaCl)

Compounds• Compounds contain 2 or more

different elements in a fixed proportion.

• Compounds are identified with “exact” chemical formulas.

• Examples: CO2, H2O, NaCl C12H22O11.

• Compounds can be separated chemically.

Compounds are a chemical combination of elements.

Mixtures vs. Compounds

• A mixture of iron and sulfur.

• Iron pyrite (FeS2)

Homework

• Worksheet: Classification of Matter (due tomorrow).