1 / 25

Introduction to Science

Introduction to Science. Chapter 1. The Nature of Science. Scientists try to answer questions about the natural world by: Exploring the unknown Explaining the known Experimenting to test theories or confirm facts. 3 Main Branches of Science.

holland
Download Presentation

Introduction to Science

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Science Chapter 1

  2. The Nature of Science Scientists try to answer questions about the natural world by: • Exploring the unknown • Explaining the known • Experimenting to test theories or confirm facts

  3. 3 Main Branches of Science • Biological- Botany, Ecology, Zoology, etc. • Physical- Physics (motion), Chemistry (matter) • Earth- Geology, Astronomy, Meteorology

  4. The Way Science Works: Scientific Method Used to learn about the natural world; includes the following steps: • Making observations • Asking questions • Forming a hypothesis; making a prediction • Testing the hypothesis through experimentation • Collecting and analyzing data from experiment • Drawing conclusion(s) from data • Communicating data to peers or public

  5. Scientific Method (cont’d) • Only 1 question investigated at a time. • Controlled experiments- compare experimental group (variable) to control group (lacks variable). *independent variable= variable/factor tested *dependent variable= variable measured quantitatively (numbers) • Experiments can only disprove an hypothesis.

  6. Scientific Thinking • Inference= conclusion drawn from previous data, not on direct observation. • Theory= explains why something happens. • Law= describes how something works.

  7. Units of Measurement-System International (SI) Units

  8. Metric System(based on 10)based on powers of 10 BIGGER SMALLER

  9. Metric Conversions (Only SI units are used to express scientific data) To convert from 1 unit to another: 1. Identify given unit; unknown unit. 2. Use dimensional analysisto compare known tounknown unit (factor-label method)   Ex. How many pounds are in 1000 grams?

  10. Know Want Don’t want • How many meters is 800 km?

  11. An object’s mass is 250 kg. What is its mass in grams?

  12. Organizing Data: Graphs • Line Graph: for continuous data • Bar Graph: compare similar data for several things • Pie Graph: compare parts of a whole Favorite Stores Car Speed Our Ages

  13. Graphing Data • Independent Variable: changed by scientist; x-axis • Dependent Variable: “depends” on independent variable; y-axis Distance (m) Time

  14. How to Make a Line Graph • Label x-axis with dependent variable • Label y-axis with independent variable • Choose increments to represent data on each axis. • Plot points. • Connect points. • Name graph. Distance (m) Time (s)

  15. Scientific Notation • Reduces # of 0’s in very large or small numbers. • Expresses simple #’s x power of 10. (simple #- 1 < number < 10)

  16. Writing Scientific Notation 1. Identify first number between 1 and 10. 2. Place decimal after that number. 3. Count number of places the decimal had to move- this is the exponent of 10. ex. 210,000,000,000,000,000,000,000 m 2.10,000,000,000,000,000,000,000 m (decimal was moved 23 places to the left) sci notation= 2.1 x 1023

  17. Writing Scientific Notation (cont’d) • If decimal moves to right, exponent is negative (original number is less than 1) • If decimal moves to left, exponent is positive (original number is 1 or greater) ex. 0.0000000902 cm 0x00000009.02cm (decimal was moved 8 places to the right) sci notation = 9.02 x 10-8 cm

  18. Write 28750.9 in scientific notation. • 2.87509 x 10-5 • 2.87509 x 10-4 • 2.87509 x 104 • 2.87509 x 105

  19. Write 2.87509 x 104 in standard notation • 287,509. • 28750.9 • 2875.09 • 28.7509

  20. Calculating Scientific Notation (Follow math rules for powers of 10) *multiplication= add powers of 10 **division= subtract powers of 10 ex. 7.2 x 10-9 1.2 x 102 7.2 x 10-9 1.2 x 102 sci notation = 6 x 10 -11

  21. Significant Figures • Number of meaningful digits in a quantity. • Significant figures are: 1. Any # that is not a zero. ex. 1246 (4 SF) 2. Zeros between nonzeros. ex. 1206 (4 SF) 3. Zeros to right of decimal ex. 0.1200 (4 SF)

  22. Significant Figures (cont’d) • Significant figures are not: 1. Zeroes after nonzerosunless a decimal is present. ex. 80,000(1 SF) ex. 83,000(2 SN) ex. 83000.(5 SN) ex. 83.000(5 SN)

  23. Putting It All Together: Chewing Gum • I’ve noticed that when I chew gum, the size changes. • How does the amount of time gum is chewed affect the mass? • Looking through the literature on gum, I see that others have noticed what I’ve noticed, but no one has done an experiment on this.

  24. My hypothesis: I think the gum will get smaller as it gets chewed because the sugar will dissolve. • I create an experiment where I time chewing gum and weighing it at different intervals. • I perform the experiment and collect data • YOU will do this in the lab!

More Related