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Warm up. Work individually to finish q uestions on pg 19 in Matter and Energy Textbook Complete questions 1-6. Three Day Weekend Catch Up!. Objective.
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Warm up • Work individually to finish questions on pg 19 in Matter and Energy Textbook • Complete questions 1-6
Objective • Students will be able to identify a chemical verses a physical change occurrence as evidenced by taking notes in class and correct answers on the Change Worksheet
Heads up: Test Thursday • Test Covers part of Scientific Inquiry and what we have covered up to this point in Physical Science • Review Notes • *Know steps to scientific method and difference between different types of variables
The sciences concerned with the study of inanimate natural objects, including physics, chemistry, astronomy, and related subjects
Which state of matter has particles arranged in a regular pattern?
Which state of matter has particles move about at the highest speed?
Elements are pure, meaning they only contain one type of atom
Compounds are mixed, meaning it is a substance that contains two or more atoms bonded together
More on Gases • WRITE THIS IN YOUR JOURNALS: • Gas Behavior: • Higher pressure= lower volume (at constant temperature) • Higher temperature= higher pressure (at constant volume) • Temperature: measurement of kinetic energy of a substance • Kinetic Energy: energy of motion Higher temperature= high volume at constant pressure from Mr. Derickson’s notes
Physical Change Verses chemical change • “Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. These changes are chemical: • iron rusting (iron oxide forms) • gasoline burning (water vapor and carbon dioxide form) • eggs cooking (fluid protein molecules uncoil and crosslink to form a network) • bread rising (yeast converts carbohydrates into carbon dioxide gas) • milk souring (sour-tasting lactic acid is produced) • Sun tanning (vitamin D and melanin is produced)” • http://antoine.frostburg.edu/chem/senese/101/matter/faq/physical-chemical.shtml
Physical change rearranges molecules but doesn't affect their internal structures. Some examples of physical change are: • whipping egg whites (air is forced into the fluid, but no new substance is produced) • magnetizing a compass needle (there is realignment of groups ("domains") of iron atoms, but no real change within the iron atoms themselves). • boiling water (water molecules are forced away from each other when the liquid changes to vapor, but the molecules are still H2O.) • dissolving sugar in water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.) • dicing potatoes (cutting usually separates molecules without changing them.) • http://antoine.frostburg.edu/chem/senese/101/matter/faq/physical-chemical.shtml
Bill Nye: Chemical reactions produce a chemical change • https://www.youtube.com/watch?v=Rtcf6Pjahec • 0:00-3:45
Example of a chemical reaction • Baking soda and vinegar demo • This demonstrates concepts within the Law of Conservation of Matter and Law of Conservation of Energy
Law of conservation of matter • The Law of Conservation of Mass states that matter can be changed from one form into another, mixtures can be separated or made, and pure substances can be decomposed, but the total amount of mass remains constant • http://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text1/Tx14/tx14.html • WRITE THIS IN YOUR SCIENCE JOURNALS
Law of Conservation of Energy • The law of conservation of energy states that the total amount of energy in a system remains constant ("is conserved"), although energy within the system can be changed from one form to another or transferred from one object to another • http://www.energyeducation.tx.gov/energy/section_1/topics/law_of_conservation/
Evidence of a Chemical Reaction • Formation of a precipitate • Generation of gas • Color Change • Absorption or release of heat • Formation of bubbles • Formation of a solid
Formation of a precipitate • Precipitation Reactions occur when cations and anions of aqueous solutions combine to form an insoluble ionic solid, called a precipitate • http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Reactions_in_Aqueous_Solutions/Precipitation_Reactions • A PRECIPITATE IS CREATED WHEN A SOLID IS FORMED FROM TWO SOLUTIONS
FORMATION OF A PRECIPIATE EXAMPLE • Cooking an egg results in formation of the gel around the yolk into egg white (protein precipitation) • https://answers.yahoo.com/question/index?qid=20091222201303AAgbKGw
Generation of a gas • Experiment (reaction) that results in gas production
Color change • Experiment (reaction) that changes the original material’s color
Absorption or release of heat • Experiment (reaction) that cools or heats substances
Formation of Bubbles • An experiment (reaction) that produces bubbles • Example: Antacid Tablet
Formation of a solid • Chemicals change to solid state • Example: Snail shells created from calcium carbonate and proteins built from inside out layers harden to form shell
Worksheet • With the remaining time work on the Chemical verses Physical change worksheet • You may work with a partner for this activity if you wish