Physical v. Chemical Properties & Changes

Physical v. Chemical Properties & Changes

physical science

Physical Properties

• anything you can observe or measure about a material

• density, melting point, boiling point, & freezing point can all be MEASURED without changing the substance into a new substance

Multiple Choice

How do you know a property is physical?

• you can observe it without changing the material

• it indicates a chemical change

Chemical Properties

• chemical properties indicate they will change the substance into something else

• if something is flammable, it can catch on fire and when it burns, it will turn into a new substance

Multiple Choice

How do you know a property is chemical?

• you can observe it without changing the material

• it indicates a chemical change

Physical Changes

• the identity of the substance stays the same

• example: ice is water in a solid form. when it melts, it's still water, just in the liquid form. melting is a physical change!

• you ARE NOT changing what the substance is, just what it looks like!

Multiple Select

Check all the PHYSICAL CHANGES:

• melting an ice cube

• burning a piece of paper

• painting a wall green

• cutting filter paper

• baking a cake

Chemical Changes

• change one substance into something else

• example: iron on the outside of a car will react with oxygen in the air to create rust, which is a new substance

Multiple Select

Check all the CHEMICAL CHANGES:

• melting an ice cube

• burning a piece of paper

• painting a wall green

• cutting filter paper

• baking a cake

Law of Conservation of Mass

• basically: what you have before HAS TO equal what you have after a reaction

• if 5 substances have a mass of 150g before a reaction that creates 1 substance, that 1 substance will have a mass of 150g