Fig. 9.3 Investigating Matter Chapter 11

Homework Assignment Chap 11 Review Questions (p 237): 3 – 20 Multiple Choice Questions: 1 - 8

Fig 11.5 The three phases of water gas liquid solid Macroscopic view Microscopic view

Change of Phase Evaporation Condensation Melting Freezing Sublimation Deposition All phase changes require addition or removal of heat e.g., the heat of vaporization of H 2 O is 2256 J/g

Physical property – describes the look or feel of a substance Chemical property – describes how a substance reacts with another substance Phase, color, texture, odor Melting point, boiling point Density flammability of methane gas rusting of iron reaction between vinegar and baking soda Physical and Chemical Properties

Physical or Chemical? Physical change - does not alter the composition or identity of a substance. Chemical change - alters the composition or identity of the substance(s) involved. ice melting sugar dissolving in water hydrogen burns in air to form water

A process in which one or more substances is changed into one or more new substances is a chemical reaction reactantsproducts Hydrogen reacts with oxygen to form water Chemical bonds are broken in the reactants Chemical bonds are formed in the products