Introduction to Chemistry Science 10 Introduction to Chemistry

Classification of Matter ELEMENT - Something which cannot be broken down any further i.e. oxygen, hydrogen, iron PURE SUBSTANCE - All particles that make up the substance are the same i.e. pure water, mercury, salt COMPOUND - When two or more elements are chemically combined i.e. water, carbon dioxide MATTER Anything that has mass and occupies space SOLUTIONS - Have only one visible compound i.e. coke, milk, alloys MIXTURE - A substance that contains two different pure substances or types of particles i.e. milk, pizza, perfume HETEROGENEOUS MIXTURES - Contain two or more visible components i.e. pizza, salad dressing, garbage

Physical Properties A physical property describes the substance i.e. State Hardness Melting point Boiling point Odour Solubility Colour Malleability Ductility Etc.

Chemical Property A chemical property is how the substance reacts to form a new substance. E.g. How it reacts with acid Flammability Bleaching ability Corrosion

Physical Change is when the original substance does not turn into a new substance but does change form i.e. Ripping a piece of paper Dissolving a salt Melting ice

Chemical Change When a substance changes from one substance into another i.e. Baking soda in acid Iron exposed to oxygen Combustion

How to Recognize a Chemical Change Clues that a chemical change has occurred. A new colour appears Heat or light is given off Bubbles of gas are formed A precipitate (solid) forms in a liquid The change is difficult to reverse

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

Homework Read section 5.1 Answer pg. 178 #2-9