Chemistry Chapter 1 Properties of Matter 1

I CAN describe various properties use to identify and classify 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 Corrosiveness Reactivity Stability Exothermic Endothermic

Much of science deals with the MACROSCOPIC and MICROSCOPIC world. 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 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.

Information obtained from the study of matter is of two basic types: QUALITATIVE expressions describe WHAT THE SUBSTANCE IS MADE OF. QUANTITATIVE expression tell HOW MUCH of a substance is present.

Substance #1 contains 10.2 grams of Calcium, 5.4 grams of Sulfur and 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 %

Some 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]

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!! http://www.angelo.edu/faculty/kboudrea/demos/sodium_chlorine/sodium_chlorine.htm 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