ChemistryChapter 1

Properties of Matter

Learning Goal

• I CAN describe various properties use to identify and classify matter.

MATTER and its PROPERTIES• What is a PROPERTY?

• A QUALITY or TRAIT associated with a particular type of matter.

• Properties that matter possess can be placed into TWO groups:– PHYSICAL PROPERTIES – those characteristics that can

be observed WITHOUT changing the identity of the substance.

-Shape, size, color, temperature, luster, texture, and

state of matter are examples of PHYSICAL

PROPERTIES.

CHEMICAL PROPERTIES – properties which describe how a substance behaves when undergoing a chemical reaction.

• Flammability – does it burn?• Corrosiveness – does it destroy the surface?• Reactivity – does it combine chemically?• Stability – does it remain the same over time?• Exothermic – does it give off heat/light?• Endothermic – does it absorb heat or light?

Much of science deals with the MACROSCOPIC and MICROSCOPIC world.

Macroscopic – large enough to be seen with the naked eye.

Microscopic – can only be seen with magnification.

Chemistry also deals with the SUBMICROSCOPIC world – those things that cannot be seen with even the most powerful microscopes.

Scientific Models

• Since the submicroscopic world cannot be seen, our understanding of it is largely based on SCIENTIFIC MODELS.– Models DO NOT have to be physical objects; they can be ideas on paper

too!

• Scientific models are THINKING DEVICES that helps us understand and explain that which cannot be seen.

Scientific Models are often based on INDIRECT evidence.Indirect Evidence is information gathered from experimental studies that

SUGGESTS a particular idea or explanation of a natural phenomenon.

For example, much of what has been learned about atoms has result from how substances behave when exposed to X-rays, electricity, heat, light, etc.

• The study of matter provides of two basic types of information:

• QUALITATIVE expressions DESCRIBE THE SUBSTANCE’S COMPOSITION.

• QUANTITATIVE expression tell HOW MUCH of a substance is present.

PROBLEM

Describe the QUALITATIVE and QUANTITATIVE expressions in the following:

• Substance #1 contains 10.2 grams

of Calcium, 5.4 grams of Sulfur and

10.5 grams of Oxygen.

• Substance #2 contains 45.5% Oxygen and

54.5 % Carbon.

• Substance #1 contains 10.2 grams

of Calcium, 5.4 grams of Sulfur and

10.5 grams of Oxygen.

Qualitative – Calcium, Sulfur and Oxygen

Quantitative – 10.2, 5.4 and 10.5 grams

• Substance #2 contains 45.5% Oxygen and 54.5 % Carbon.

Qualitative – Oxygen and Carbon

Quantitative – 45.5% and 54.5 %

Other Ways to Classify Substances• Substances can also be classified as either PURE

SUBSTANCES or MIXTURES.

• A PURE SUBSTANCE contains ONLY ONE KIND OF ATOM [element]. – example Copper – only contains Cu atoms

or one kind of MOLECULE [compound]– example WATER – only contains H2O molecules

• A MIXTURE contains two or more different substances not chemically joined with each other [elements or compounds] and can be easily separated.

Properties of PURE SUBSTANCES

• Made of only ONE KIND of atom or molecule.• Compounds do NOT have the properties of the elements

they are made up from!!

• (VIDEO)

• Components are NOT EASILY SEPARATED!

Properties of MIXTURES

• Can be a combination of elements, compounds or both in any ratio.

• The individual components in the mixture KEEP THEIR OWN PROPERTIES.

• Usually easily separated into the various components in the mixture.

CLASSIFY the following as PURE SUBSTANCES

[elements or compound] or MIXTURES:• Aluminum• Table Salt• Sugar• Kool-Aid• Blood• Carbon Dioxide• Soil• Milk

• Water

• Gasoline

• A cake

• Mouthwash

• 14 Karat Gold

• Baking Soda

• Baking Powder

• Aluminum Pure (element)

• Table Salt Pure (compound)

• Sugar Pure (compound)

• Kool-Aid Mixture

• Blood Mixture

• Carbon Dioxide Pure (com)

• Soil Mixture

• Milk Mixture

• Water Pure (compound)

• Gasoline Mixture

• A cake Mixture

• Mouthwash Mixture

• 14 Karat Gold Mixture• Baking Soda Pure (Compound)

• Baking Powder Mixture