The Scientific Method

1. The Scientific Method

2. Round objects fall when nudged off the desk. The statement above is a(n) (Select as many as apply.) • observation • hypothesis • experiment • summary statement • scientific law • explanation • theory

3. Round objects fall when nudged off the desk.The statement above is a(n) • observation • hypothesis • experiment • summary statement • scientific law • explanation • theory You could make a case for any or all of these choices except #6 or 7.

4. The objects fell to the floor because any two objects are attracted to one another by gravity. (Select all that apply.)The statement above is a(n) • observation • hypothesis • experiment • summary statement • scientific law • explanation • theory

5. The objects fell to the floor because any two objects are attracted to one another by gravity.The statement above is a(n) • observation • hypothesis • experiment • summary statement • scientific law • explanation • theory

6. Actually doing science includes(Choose any that apply.) • experiments • laws • observations • theories • predictions • hypotheses • repetition

7. Actually doing science includes(Choose any that apply.) • experiments • laws • observations • theories • predictions • hypotheses • repetition All of these are part of the scientific process

8. Select the statement(s) which is(are) observations about the picture shown below. • The person is wearing a blue top. • There is steam above the beaker. • They are testing the products of combustion. • The student is interested in learning science. • She has 4 test tubes. • The kid is having fun. • The materials in the large containers are greenish and yellowish.

9. Select the statement(s) which is(are) observations. If you are making an assumption, as the words in blue do, then the statement is no longer an observation. • The person is wearing a blue top. • There is steam above the beaker. • They are testing the products of combustion. • The student is interested in learning science. • She has 4 test tubes. • The kid is having fun. • The material in the large containers are green and yellow.

10. Chemistry is the study ofSelect as many as apply. • Stuff • The changes the stuff goes through • The energy associated with those changes 10

11. Chemistry is the study of All of these • Stuff • The changes the stuff goes through • The energy associated with those changes 11

12. Chemistry is defined as the science that deals with the materials of the universe and the changes that these materials undergo. 12

13. Scientific Method • Chapter 1

14. Scientific method is the process that lies at the center of scientific inquiry

15. Doing Science Hypothesis & Law & Theory • Dealing with the Subtleties of this Vocabulary

16. Doing Science • Make an observation • Propose an explanation • Do an experiment • Repeat - after enough of this you might make: • A law - summary OR • A theory - explanation • One of the most important reasons for making theories and laws is to be able to make predictions • Of course no theory is above scrutiny, so further experiments should be continued to confirm the validity of the theory.

17. Hypothesis - Law - Theory • Hypothesis • Testable question or explanation for an observation • Law • Summary statement of many observations • Theory • An explanation of many observations • A Law tells us what happens. • A theory tells us why it happens.

18. Law and Theory • Don’t think that a Law is a Theory that has been proven. • Don’t think that a Law is any more exact than a Theory. • Don’t think that a Theory is a proven Hypothesis. • Don’t think that a Law is proven and a Theory is not proven. • Laws and Theories are distinctly different. • Law is what. Theory is why.

19. Two Words to Avoid: Prove & True • Avoid using the words prove and true. • The methods of science never prove anything. • The word "proof" refers to a strictly mathematical process. • Science doesn’t claim absolute truths. Avoid the word "truth or true" in scientific discussion. • An experiment may disprove a Law, but no finite number of experiments ever establish a Law as absolutely true. • In a single experiment you might "verify" or "confirm" the validity of a Law, but not actually prove it. • So in this class…do NOT use the words prove and true.

20. The scientific method usually begins with(select the choice(s) that best apply.) • A hypothesis • A law • An observation • A question • An experiment • A theory 20

21. The scientific method usually begins with(select the choice(s) that best apply.) • A hypothesis if you were thinking of earlier work. • A law • An observation • A question • Or maybe an experiment • A theory 21

22. A hypothesis is(choose all that are appropriate) • always written in question form. • used to develop a law. • made before doing an experiment. • a summarization of observations. • a test to determine the reason for an observation. • a possible explanation that can be tested. 22

23. A hypothesis is(choose all that are appropriate) • always written in question form. • sometimes used to develop a law. • often made before doing an experiment. • a summarization of observations might be uses as you make an hypothesis • a test to determine the reason for an observation. • a possible explanation that can be tested. 23

24. Select the one statement that is FALSE. • A theory is sometimes called a model. • A law is a theory that has passed the test of time. • A law is a general summary of observations. • A law tells us what, a theory tells us why. 24

25. Select the one statement that is FALSE. • A theory is sometimes called a model. • A law is a theory that has passed the test of time. Laws and theories are fundamentally different. A law is a summary, a theory is an explanation. • A law is a general summary of observations. • A law tells us what, a theory tells us why. 25

26. Remember that science does not always progress as smoothly and efficiently as presented in the textbooks or in video. • Scientists are human. • They have prejudices. • They misinterpret data. • They become emotionally attached to their theories and lose objectivity. • They play politics. • 2. Science can be affected by • Money • Wars • Fads • Religious beliefs • Government motives • Cultural beliefs • Racial prejudices • Fear • Gender bias

27. Galileo was forced to recant his astronomical observations because • Men were not allowed to wear beards in 1600. • There was strong religious resistance to his ideas. • Authorities thought his telescope was a weapon. • He belonged to the wrong political party.

28. Antoine Laurent Lavoisier, sometimes called the father of modern chemistry, was beheaded in 1794 because • He was developing explosives to fight a war. • The governor did not like his wig. • He spent too much time with the mayors daughter. • He was affiliated with the wrong political party. ∆ to slide show 28

29. Candle • Observations • Questions - Hypotheses • Experiments • Summary Statements - Laws • Explanations - Theories

30. When a cover is put over the candles, I predict that • They will go out all at the same time. • The top one will go out first, then middle, last bottom. • The bottom one will go out first then middle, then top last. • They will go out in random order.

31. When the cover is put over the candles, I predict that • They will go out all at the same time. • The top one will go out first, then middle, last bottom. this does not always work perfectly, however the thinking is that the hot gases that go through the flame and rise to the top are devoid of oxygen, thus the oxygen-less air happens from the top down. • The bottom one will go out first then middle, then top last. • They will go out in random order.

32. Glass over candle caused it to go out.Relight candle, cover with glass, candle went out • approximately same length time • definitely shorter time • definitely longer time • seemed to be no pattern

33. Glass over candle caused it to go out.Relight candle, cover with glass, candle went out • approximately same length time • definitely shorter time • If the oxygen was used up in the first burn, then the candle wil not be able to burn as long due to the lack of available oxygen • definitely longer time • seemed to be no pattern

34. Wax in which form burns best? • gas • liquid • solid - large lump • solid - powdered

35. Wax in which form burns best? • gas Gas would always be best because for any reaction (combustion included) the reactants must mix and collide. That mixing is easiest if gas. The bowl of liquid wax is “wicked” up the wick and then vaporized in the heat of the flame and then burned. • liquid Liquid would also be good, especially if stirred to promote mixing, and especially if warmer as the warmth would make the particles move faster and mix better. • solid - large lump • solid - powdered Powdered also works well because of the increased surface area that can come in contact with the oxygen.

36. 1 2 3 4 5 Which portion of the candle did you find burned the hottest?

37. 1 2 3 4 5 Which portion of the candle did you find burned the hottest? # 2 is probably the hottest part of a candle flame.

38. What are the products of combustion of candle wax? Candle wax is: C25H52Select as many as you think may apply. • C • H2 • H • CO2 • CO • H2Oliquid • H2Ovapor • O2 • O

39. What are the products of combustion of candle wax? Candle wax is: C25H52Select as many as you think may apply. • C, sometimes ~ pure carbon or soot was also a product, especially when you interrupted the complete combustion by sticking in the paperclip (C fails to react with O2). • H2 • H • CO2 • CO • H2Oliquid • H2Ovapor • O2 • O switch to slide show

40. Representing Reactions • Wax reacts with oxygen to produce carbon dioxide and water and energy.

41. Representing Reactions • Wax reacts with oxygen to produce carbon dioxide and water and energy. • reactants → products

42. Representing Reactions • Wax reacts with oxygen to produce carbon dioxide and water and energy. • reactants → products • use chemical formulas to write an equation

43. Representing Reactions • Wax reacts with oxygen to produce carbon dioxide and water and energy. • reactants → products • use chemical formulas to write an equation • C25H52 + O2 → CO2 + H2O + E

44. Law of conservation of mass Matter can be converted from one form to another BUT can neither be created nor destroyed. C25H52 + O2 → CO2 + H2O + E Requires us to “balance” the equation

45. Law of conservation of mass Energy can be converted from one form to another BUT can neither be created nor destroyed. C25H52 + O2 → CO2 + H2O + E Requires us to “balance” the equation • C25H52 + O2 → 25CO2 + H2O + E

46. Law of conservation of mass Energy can be converted from one form to another BUT can neither be created nor destroyed. C25H52 + O2 → CO2 + H2O + E Requires us to “balance” the equation • C25H52 + O2 → 25CO2 + H2O + E • 2. C25H52 + O2 → 25CO2 + 26H2O + E

47. Law of conservation of mass Energy can be converted from one form to another BUT can neither be created nor destroyed. C25H52 + O2 → CO2 + H2O + E Requires us to “balance” the equation • C25H52 + O2 → 25CO2 + H2O + E • 2. C25H52 + O2 → 25CO2 + 26H2O + E • 3. C25H52 + 38O2 → 25CO2 + 26H2O + E