Unit 3: Heat and Temperature

Big Idea 1.0 Heat causes matter to change Many changes in matter are caused by heat Ex putting ice cubes into warm soup; drying clothes in the sun; putting water in the freezer Matter can exist in three forms: (states of matter) Solid Liquid gas

Heat can cause a change in the state of matter Changes include: Freezing: liquid changes into a solid Melting: Solid changes into a liquid Evaporation: Liquid changes into a gas Condensation: Gas changes into a liquid Sublimation: Solid changes into a gas

Water Freezing/ melting point= 0oC (liquid to solid) Boiling / condensation point= 100 oC (liquid to gas)

Sulphur Solid to liquid at 113 oC Liquid to Gas at 445 oC Most often found as a solid in nature

Mercury Changes from solid to liquid at -39 oC Changes from liquid to gas at 357 oC Most often found as a liquid in nature

Chlorine Solid to liquid at -101 oC Liquid to gas at -35 oC Generally exists as a gas in nature

A ‘cool’ heat challenge Melt an ice cube as fast as you can. Here are the rules: You can only use what is at your desk right now You must collect as much melted ice as possible You can’t put it in your mouth Answer these questions How did you melt the ice? Why did you choose this? Did any strategies work better? Why? If you could do this again what would you change? If you could use anything to melt the ice, what would you use? How would it change your results?