Chemical and Physical Reactions

Write out a list of your ideas on this slide. Teacher directs students to write a list of their own on their slide notes. Have them share their lists with each other before sharing them out. When we talk about reactions in science what does that make you think of?

Reaction A reaction is when______ _____________________ ____________________. A reaction is when two or more molecules or atoms interact and something happens.

There are two kinds of reactions, chemical and physical. Let’s see if we can figure out which is which. Chemical and Physical

Chemical or Physical Change? Crushing a can Baking a Cake Freezing water to make ice Cutting Paper Mixing paint to make a new colour Physical Chemical Physical Teacher has students read slide and guess what kind of reaction it is. Physical Chemical

Compare Physical Chemical 1. 2. 3. 4. 5. Teacher asks: What did you notice about physical reactions? What did you notice about chemical reactions? Work with your table group and make a list of each one. Have them work for a few minutes and then students share out ideas. Write or type ideas into power point slide. Compare

Are the formation of a new substance and they tend to be irreversible. Color change Release of gas Temperature change Turns cloudy Change of ph Teacher asks: How does this definition compare to your list of characteristics? Chemical Changes

Physical Changes They do not result in a new substance and are reversible. Melting and freezing Boiling and condensation Forming a separable mixture Teacher asks: How do these notes compare with the list of characteristics you made?

Make a T-Chart of Physical and Chemical Reactions Making toast Boiling an egg A light bulb getting hot Boiling water Adding sugar to a cup of tea Food going moldy Setting off a firework Treating wasp and bee stings Diluting orange juice with water Tell students they will work with a partner to create a T-Chart of examples of chemical and physical reactions. Have students first sort pictures into two categories of the T-Chart. Teacher circulates and approves or asks students to think again about their answers. Students paste their answers to their T-Chart when they get approval from teacher. Come back as a class and review answers. 24/04/2017

Exit Ticket: Chemical or Physical? 1. Bottle Breaking _________________ Burning Paper Puddle Evaporating ___________________ Boiling Water Print this slide out separately for an exit ticket. Is a rusty car a physical or chemical reaction? What characteristic make it a physical or chemical reaction? ____________________________________________