Physical and Chemical Changes Unit II—Part 2

Concept of Change Change: the act of altering a substance

Physical Change Pre-Question A family from Minnesota turns off the heat and flies to Florida for a winter holiday. When they come home, all of their water pipes have burst. What do you think happened? Answer: The water in the pipes froze and expanded.

Physical Change Physical change: a change that occurs that does not change the identity of the substance  Melting ice ( change in state or phase) What do the particles look like when ice melts?  Freezing Kool-aid  Tearing paper  Boiling water (same as melting ice)

Why do phase changes occur? Let’s use gizmo to find out. Formative Assessment: Gizmo assessment.

Chemical Changes Chemical change: a change that occurs causing the identity of the substance to change  Burning  Digesting food  Reacting with other substances (give an example per reviewer) A chemical change is called a chemical reaction

How do you know a chemical change has taken place? Indicators of a chemical change: Evolution of light Evolution of heat Evolution of a gas Color change Formation of a precipitate  Discovery Ed. Firework Video

Chemical Reactions Video During the video answer the following questions in Cornell Note Style: 1. What are the parts of a chemical reaction? 2. Use a Venn Diagram to answer this question- What is the difference between and endothermic reaction and exothermic reaction. 3. What factors increase a chemical reaction?

Is it Physical or Chemical? ChangePhysicalChemical Melting cheese Burning wood Milk souring (Do all students relate to this?) Wadding up paper Bicycle rusting