1. Introduction to Chemistry SNC2DI

2. Organization of Matter

3. Physical Properties A physical property describes the substance E.g. –State –Hardness –Melting point –Boiling point –Odour –Solubility –Colour –Malleability –Ductility –Etc.

4. Chemical Property A chemical property is a description of how the substance reacts to form a new substance. E.g. –How it reacts with acid –How it reacts with water –How it reacts with oxygen –Etc.

5. Physical Change A physical change is when the original substance does not turn into a new substance but does change form. E.g. –Ripping a piece of paper –Dissolving a salt –Melting ice

6. Chemical Change When a substance changes from one substance into another, it is a chemical change. E.g. –Baking soda in acid –Iron exposed to oxygen –Combustion

7. How to Recognize a Chemical Change Clues that a chemical change has occurred. 1.A new colour appears 2.Heat or light is given off 3.Bubbles of gas are formed 4.A precipitate (solid) forms in a liquid 5.The change is difficult to reverse E.g. 2H 2(g) + O 2(g)  2H 2 O (l)

8. Chemical Tests You can use chemical change to perform a chemical test to determine if a substance is present. –Glowing splint used to indicate if oxygen is present –A burning splint is used to indicate if hydrogen is present –Limewater can be used to indicate if carbon dioxide is present –Cobalt chloride paper can be used to indicate if water is present –A flame test can tell which type of metal is present Flame test for Li

9. Homework Read section 5.1 Answer questions 2-8 on page 178

10. Credits http://commons.wikimedia.org/wiki/File:Snow_crystals_2b.jpg http://commons.wikimedia.org/wiki/File:Magnesium_Sparks.jpg http://commons.wikimedia.org/wiki/File:Melting_icecubes.gif http://commons.wikimedia.org/wiki/File:Lighting-match.gif http://commons.wikimedia.org/wiki/File:FlammenfärbungLi.png