Chapter Two: Matter and Change

Properties of Matter If you had to describe matter, what would you say?

Describing Matter PROPERTIES USED TO DESCRIBE MATTER CAN BE CLASSIFIED AS EXTENSIVE OR INTENSIVE Extensive properties include: The mass of the object The volume of the object It depends on the amount of matter in a sample Intensive properties include: Hardness Smoothness Depends on the type of matter in a sample Ex. All samples of pure gold have identical intensive properties because their chemical composition is identical.

Identifying Substances Matter that has uniform and definite composition is called a substance EVERY SAMPLE OF A GIVEN SUBSTANCE HAS IDENTICAL INTENSIVE PROPERTIES BECAUSE EVERY SAMPLE HAS THE SAME COMPOSITION Examples of physical properties include: Hardness, boiling point, freezing point, colour, conductivity, malleability Physical properties can be observed and measured without changing the substance's composition

Copper vs. Gold How are they different/same? Page 40, Table 2.1

States of Matter THREE STATES OF MATTER ARE SOLIDS, LIQUIDS AND GASES Solids have definite shape, volume and not easily compressed Liquids have indefinite shape, definite volume and not easily compressed Gases have indefinite shape, indefinite volume, and are easily compressed The particles composing each varies from state to state See Figure 2.3 on page 41

Physical Changes During a physical change, some properties of the material changes, but the composition does not What are some words that could be used to describe physical changes of a substance? Look at Figure 2.4, and answer the questions – Is the melting of gallium a reversible or irreversible change? What is the physical state of gallium at room temperature?

Mixtures A mixture is a physical blend of two or more components BASED ON THE DISTRIBUTION OF THEIR COMPONENTS, MIXTURES CAN BE CLASSIFIED AS HETEROGENEOUS MIXTURES OR AS HOMOGENEOUS MIXTURES Heterogeneous mixtures do not have uniform composition (trail mix). Each part is called a phase. Homogeneous mixtures, or solutions, have uniform composition (stainless steel). By definition, they have one phase.

Separating Matter DIFFERENCES IN PHYSICAL PROPERTIES CAN BE USED TO SEPARATE MIXTURES Floating, freezing, filtration, distillation, using magnets, etc. Check for comprehension: Questions 1 -8, pg. 42 Questions 9-10, pg. 46 Questions 11 – 17, pg. 47 Guided reading, sections 2.1, 2.2