Scientific Method & Measurement

1. Scientific Method & Measurement

2. VOCABULARY • Scientific Method • Control • Independent Variable • Dependent Variable • Constants • Hypothesis • Precision • Accuracy

3. Precision vs. Accuracy Precision= how close a measurement is tothe others (place) Accuracy= how close a measurement is totrue value (actual) For each target, decide whether the “hits” are low or high or both in precision & accuracy. (Hint: accurate “hit” = bulls eye!)

4. Precision vs. Accuracy Below are four sets of data obtained by students in a CHM 151 lab. The small metal object has an actual mass of 25.11 g. Comment on the accuracy and precision of the data sets.

5. Fact vs. Inference

6. Fact vs. Inference

7. Fact vs. Inference

8. Observation • Observation is how we view the world with our senses. • Observation equips us with the material for thought, reflection and judgment. • Observers exposed to the same sense impressions do not necessarily see, hear, feel, taste or smell the same things. • Observation is influenced by experience, knowledge and emotion. Attention plays an important part in observation. • One can be trained to be a more effective observer. Some people are more reliable witnesses than others. The trained observer sees significant details. • A sharp eye for details is an important skill for many professions: scientists, physicians, artists, instructors, accountants, among others.

9. Inference • We draw inferences on the basis of observations, or on conclusions drawn from previous observations. • Inference is the interpretation of facts. (A statement of fact is an observation statement that can be verified by the use of the senses.) • Valid inferences are based on sufficient and relevant evidence. • Inferences express probability, not certainty. • Our training and background provide a basis for our inferences. • Inferences enable us to assess and evaluate conditions and make predictions.

10. Observation vs. Inference Observation- use our senses based on facts Inference- opinion/guess • Sean is not in school today. • Sean must be sick. • Mr. Newton is wearing a coat. • It must be cold outside.

11. Directions: Label the following statements as either observation (O) or inference (I). 1. When I rang the doorbell, no one answered. 2. The hamburger was hot. 3. Jamal must be very popular. 4. The rabbit uses fur from her stomach to build her nest. 5. That sounded like a mean dog. 6. The rock feels like an ice cube. 7. Those clouds look like a mountain. 8. The beaker contains 250 ML of water. 9. The bark on the birch tree was white. 10. A gas was formed when I mixed the liquid and solid.

12. Directions: Label the following statements as either observation (O) or inference (I). O 1. When I rang the doorbell, no one answered. 2. The hamburger was hot. 3. Jamal must be very popular. 4. The rabbit uses fur from her stomach to build her nest. 5. That sounded like a mean dog. 6. The rock feels like an ice cube. 7. Those clouds look like a mountain. 8. The beaker contains 250 ML of water. 9. The bark on the birch tree was white. 10. A gas was formed when I mixed the liquid and solid. O/I I O I O/I I O O O

16. Evidence and Inference Song Chorus: Evidence and inference, you’ve got to know the difference We need them both for what we do, but we cannot confuse the two Evidence – it’s just the cold hard facts Evidence – only your observations Evidence – what you see, hear, or feel Evidence - you’ve got to keep it real Chorus: Inference – what you think your data means Inference – it’s your interpretation Inference – backed up by the facts you’ve seen Inference – we’ll see if scientists agree Chorus: Inferences can lead to science discoveries But only if they’re tested, check out your data carefully When ideas and data match-up and other scientists agree By repeating your experiment and now you solved a mystery Chorus: Evidence and inference and now we know the difference We need them both for what we do and we will not confuse the two

17. Qualitative vs Quantitative Observations Qualitative observations- use your ________ to observe the results. Ex) Sight, smell, touch, taste & hear. Quantitative observations- are made with ______________ such as rulers, balances, graduated cylinders, beakers, and thermometers. These results are ____________. senses instruments measurable

18. Read the following examples and then decide if the example is qualitative (1) or quantitative (2). • It is light green in color. • It tastes sour. • One leaf is 9 cm long. • It makes a loud pop sound. • The mass of the computer is 1 1/2 kg. • It smells sweet. 1 1 2 1 2 1

19. 1 or 2 7. The temperature of the room increases by 8 degrees C. 8. It gets darker over a period of time. 9. The flower clusters in 3 blooms. 10. Feels very rough. 11. The plant is short. 12. Leaves are stiff. 13. The veins are 3 mm wide. 1 1 or 2 1 1 or 2 1 2

20. 14. Write a qualitative example: 15. Write a quantitative example: 16. What type of observation do you think is more scientific and why?

21. MEASUREMENT CHART

27. Line Segments In order to be successful in measurement, you must know your line segments. The first thing you should do when measuring something is to figure out which line segment is being used.

28. .1 Line Segment 1/10 • Centimeter ruler segments & Baby Rider • There are 9 marks in between each whole # 0 .1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 etc. .1 1.3 2.1 2.9 3.7 1. _____ 2. _____ 3. _____ 4. _____ 5._____

29. .2 Line Segment 1/5 • Graduated Cylinder (GC) segments • There are 4 segments in between whole #s 0 .2 .4 .6 .8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 etc. .6 2.8 5.0 6.8 8.4 6. _____ 7. _____ 8. _____ 9. _____ 10._____

30. . 25 Line Segment 1/4 • Graduated Cylinder (GC) segments • There are 3 segments in between whole #s 0 .25 .50 .75 1.0 1.25 1.5 1.75 2.0 2.25 2.5 2.75 3.0 3.25 3.5 3.75 4.0 etc. 1.5 3.75 6.0 8.25 10.5 11._____ 12._____ 13._____ 14._____ 15.____

31. .5 Line Segment 1/2 • Graduated Cylinder (GC) segments • There is1 segment in between whole #s 0 .5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 etc. 5.5 8.0 10.0 12.5 14.5 16._____ 17._____ 18._____ 19._____ 20.____

33. .5 vs. .05 0 1 2 1.05 2.05 .05 0.5 1.5

34. King Henry Fable King Henry was an old English king who loved to drink chocolate milk. Even though metrics had been used in England for a long time, King Henry had difficulty converting between the different metric units. He had really become frustrated and confused when he went to get himself some chocolate milk. He did not know how much milk to pour himself. He felt, as a king, that he should be able to do anything. So he asked for help from all of the smart people in his kingdom. They all tried hard to explain to the king, but without a lot of luck. Then one of the great mathematicians in his kingdom came forward to try his luck. However, before he could explain to King Henry that everything in metrics was done by either multiplying by 10 or dividing by 10 which is easy to do by just moving the decimal point, King Henry died by drinking chocolate milk. King Henry Died By Drinking Chocolate Milk! Based on the Fairy Tail king Henry in Elementary CORE Academy 2003

35. Metric Prefixes King Henry Song CD: The Science Maniacs By Scott Mangione & Peter Weiland

36. King Henry Died By Drinking Chocolate Milk King Henry died by drinking chocolate milk. 10 millimeters equals 1 centimeter 100 millimeters equals 1 decimeter 1000 millimeters equals 1 meter We’ve got to keep going, we just keep getting bigger 10 meters equals 1 dekameter 100 meters equals 1 hectometer 1000 meters equals 1 kilometer In the metric system that’s the way that we convert Millimeter, centimeter, decimeter, meter Dekameter, hectometer, kilometer – LENGTH Milligram, centigram, decigram, gram Dekagram, hectogram, kilogram – MASS Milliliter, centiliter, deciliter, liter Dekaliter, hectoliter, kiloliter - VOLUME King Henry died by drinking chocolate milk. He drank 1 kiloliter in his robe of silk 1000 liters were more than he could take 1 million milliliters turned out to be a big mistake A princess in a traveling band Passed through King Henry’s land She had a gift that he’d never seen She said that it was chocolate milk And the King drank one drop just to try 1 milliliter is not a lot But poor King Henry just could not stop Chorus: King Henry drank 1000 drops 1 liter’s not a lot It barely filled up his royal crown He continued to keep drinking on ‘til 1000 more liters were gone A bathtub full of chocolate milk Drowned King Henry in his robes of silk

37. Metric Prefixes

39. Small…Large! • Quarks are very very small • Molecules are around the billionths of a meter in size. That is 0.000000001 meters. Some molecules are smaller and some bigger, though. • People are a little over a meter tall, • Mountains are kilometers in size. • The Earth is megameters in size (a megameter is a thousand kilometers, and the Earth's Diameter is actually 12,000 km) • A Light Year is about 10 petameters in size (a petameter is 1,000,000,000,000,000 meters, which is a 1 followed by 15 zeros) • The Milky Way is about 1 zetameter across (1,000,000,000,000,000,000,000 meters, which is a 1 followed by 21 zeros) • The Universe is very very big

40. Copy this staircase into your notes!

42. Metric Units • MASS = Gram(s) • VOLUME = Liter(s) • LENGTH = Meter(s) Let’s Start With Mass…

43. Meniscus Madness! Always Read at EYE LEVEL!

44. Meniscus= the curve of a liquid in a container Concave! Convex!

45. Line Segment = 1 73 mL

46. 20mL .1 Line Segment

47. Line Segment = 1 18 mL

48. Line Segment = 5 293 mL

49. Line Segment = .2 6.6 mL

50. Line segment = 1 53 mL