220 likes | 231 Views
Changes in Matter. Physical Change Can be reversed No new material created Phase change . Chemical Change Cannot be reversed New substance made One or more of the following occur: * co lo r ch an ge * temperature change ( hotter or colder ) * flashes of light or sound
E N D
Changes in Matter Physical Change • Can be reversed • No new material created • Phase change
Chemical Change • Cannot be reversed • New substance made • One or more of the following occur: * color change * temperature change (hotter or colder) * flashes of light or sound * gas produced ~ bubbles * new odor
Signs of Chemical Reactions There are five main signs that indicate a chemical reaction has taken place: release input change in color change in odor production of new gases or vapor input or release of energy difficult to reverse
Chemical Color change Odor change Cant turn it back into raw egg
Physical • Change in state of matter only • Can turn steam back into liquid • Molecules are still H2O
Burning gasoline • www.wusa9.com/news
Chemical • New material made • Odor change • Cant turn back to gasoline
Chemical • Odor change • Taste change • New chunky substance made • Cant turn back to milk
Physical • Still a spring • Returns to normal shape after it is released
Rusting bicycle timberspringsphotography.com
Chemical • Color change • Texture change • Cant turn back to metal • New material
Gases No definite shape Lots of energy Volume can change Often created in a chemical reaction
Oxygen O Colorless Odorless Tasteless Flammable Fuels a fire
Hydrogen H Colorless Odorless Tasteless Explosive in fire Makes a “popping” noise In fire
Carbon Dioxide CO2 • Colorless • Odorless • Tasteless • Dense • Puts out a fire
Test for Type of Gas Glowing wood splint