Properties and changes Both Physical and Chemical

Learning goals We are learning to identify physical and chemical properties. We are learning to identify physical and chemical changes.

Physical property describes a characteristic of a substance that can be observed or measured

Physical properties of water cohesion – water sticks to itself forms beads on non-adhesive surfaces adhesion – water sticks to other substances allows you to mop up water with a towel

Drip, drip, drip … Complete the penny/water activity please!

Physical properties

Make a chart like this … Physical Property Description Examples

Colour and lustre Light a substance reflects gives it a colour and lustre Gold is shiny Concrete is dull

conductivity Ability of a substance to conduct electricity or heat Conductors – most metals (copper used for electrical wires) Insulator – little or no conductivity (Styrofoam and glass)

density The amount of mass in a given volume of a substance Density of pure water is 1.0 g/mL Water is denser than oil, so oil floats on water Mass = Density X Volume

ductility Any solid that can be stretched into a long wire copper

hardness Substances ability to resist being scratched Diamond is the hardest

malleability A substance that can be pounded or rolled into sheets Aluminum foil, gold and tin

viscosity The resistance of a fluid to flow Syrup has a high viscosity compared to water

Chemical properties describes the ability of a substance to change into a new substance(s) Absorbs heat during reaction Combustible Forms gas when heated Reacts with acid Reacts with water Emits heat during reaction Emits light during reaction Forms a precipitate (solid) in a solution

Physical change the matter involved can experience a change in one of the following criteria: Change in SIZE (cutting a gold block in half) Change in SHAPE (making a paper airplane) Change in STATE (ice cube melting) Making a SOLUTION (salt dissolved in water) No new substance is made, and all changes are reversible.

Chemical change always results in the formation of a new substance(s) chemical reaction evidence of a chemical change include: Colour change Odour change Temp change Production of light Formation of precipitate Production of gas (bubbles)

Learning goals We are learning to identify physical and chemical properties. We are learning to identify physical and chemical changes.

Please Complete Textbook 5.2 #1-5.