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

Fill in the Blank

Which type of change does NOT change the identity of the substance?

Fill in the Blank

Which type of changes DOES change the identity of the substance?

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