Unit 1 Matter Changes of Matter Physical Changes

Unit 1 - Matter Changes of Matter

Physical Changes • These are changes in size, shape appearance, etc. • Critical to observe that there is no change in chemical identity. • You still have the same stuff !!!

Chemical Changes • These are changes in size, shape, appearance, etc, WITH changes in the chemical identity of the system. • YOU GET NEW STUFF !!!!!

Chemical Changes notes… • Five ways to tell that a • Heat chemical change is • Light occurring are: • Electricity • Bubbles • Formation of a precipitate.

Chemical Changes notes… • Five ways to get a chemical change to occur are: • • • Heat Light Electricity Dissolve in Water Use a Catalyst

Chemical Changes notes… • “Chemical change “ = “Chemical Reaction” • Must remember that all chemical reactions obey the Law of Conservation of Mass.

The Law of Conservation of Mass • States that matter is neither created or destroyed during chemical reactions. “All of the atoms that enter a reaction as reactants will exit that reaction as products” They will be bonded differently as products than they were as reactants…

A Chemical Equation to Illustrate the Law of Conservation of Mass 2 C 4 H 10 + 13 O 2 8 CO 2 + 10 H 2 O On the left side of this reaction: On the right side of this reaction: • 8 atoms of carbon • 20 atoms of hydrogen • 26 atoms of oxygen

Nuclear Changes • These are changes to the internal structure of the atoms. • The bottom line here is that the atoms of one element actually become atoms of a different element.

Your task…. . • You need to be able to classify a given description of a change as a Physical Change Chemical Change Nuclear Change