Matter and Change: Changes in Matter

Matter and Change Part 2 – Changes in Matter TAKS Student Here’s what you have to do if you Expectation this part of the want to pass 11.8 Integrated Physics and Chemistry (8) Science 1. Look at an observed change and Concepts. The Student knows know if it was physical or that changes in matter affect everyday chemical. life. The2. Know what the heck a rock cycle student is expected to: is! (A) distinguish between physical and 3. Know what “oxidation” means. chemical changes in matter such as 4. Understand the basic ideas of oxidation, digestion, changes in state and in digestion. the rock cycle TAKS: Physical Change A change in the physical appearance of a substance that does not change the identity of the substance. SOLID LIQUID GAS Physical Changes Phase Change – physical change from one state to another Below 0°C SOLID Only the temperature changes Between 0°C and 100 0°C LIQUID Above 100°C GAS Still H2O in every form!!! Physical Changes • Examples of physical changes: Crushing an aluminum can Cutting your hair Shredding paper Sample Question Source: Spring 2006 TAKS Chemical Changes Chemical changes, or chemical reactions, occur when one or more substances is converted into another substance. • Original atoms are preserved • New substances are formed • Different chemical composition than original substance Chemical Changes Chemical changes are chemical reactions. Indicated by a number of signs formation of a gas, formation of a solid, or precipitate change in temperature evolution of heat and light Change in color Change in odor • • • • • • Chemical Changes • When iron (Fe) rusts, you can see it happen over a long period of time. • The actual iron molecules change their structure as they react with oxygen and are oxidized. Chemical Changes • Examples of chemical changes: Grass growing Frying an egg Sample Question Source: Spring 2004 TAKS The Rock Cycle • Lets Look at each part of the rock cycle and – Which areas involve chemical change? – Which areas involve physical change? Sample Question Source: Spring 2004 TAKS Sample Question Source: Spring 2003 TAKS Digestion • Lets Look at each part of the digestion – Which areas involve chemical change? – Which areas involve physical change? Sample Question Source: Spring 2004 TAKS