Changes in Matter What Happens to a Substance in a Physical Change? What Happens to a Substance in a Chemical Change? How are Changes in Energy & Matter Related? Introduction to Chemistry HAA Grade 7 Maria McCarthy, 11/03/2010
What Happens to a Substance in a Physical Change? • A Physical Change alters the form of appearance of matter but does not turn any substance in the matter into a different substance. • A substance that undergoes a physical change is STILL the SAME substance.
What Happens to a Substance in a Chemical Change? • A single substance break down into two or more other substances: • H2O2 => H2O + O • Hydrogen Peroxide breaks down into water and oxygen gas when you pour on a cut. • Photosynthesis is a naturally occurring chemical change. Several organic compounds combine with energy from the sun to form new substances. • Combining Borax powder, glue, and water makes a polymer. • Chemical change produces new substances with new and different properties.