Chapter 1

1. Chapter 1 The World of Physical Science

2. What is Science? Science is a process of gathering knowledge about the natural world. Can you give some examples of sciences?

3. Science Life Earth and Space Physical Biology Astronomy Physics Anatomy Meteorology

4. What is Physical Science? Physical science is the study of matter and energy. Matter is made up of atoms and has both a mass and volume. Energy is the ability to do work. The branches of physical science Chemistry Physics

5. Chemistry Chemistry is the study of all forms of matter, including how matter interacts with other matter. Chemistry looks at the structure and properties of matter.

6. Physics Physics looks at energy and how that energy affects matter. Motion, force, gravity, electricity, light, and heat are parts of physics.

7. What are the “steps” of the Scientific Method? The scientific method are the ways in which scientists answer questions and solve problems. Observation Ask a question Form a hypothesis Test the hypothesis Analyze results Draw conclusions Communicate results

8. Steps of the Scientific Method 1) Observation The use of the senses to gather information. Qualitative – color, odor, taste, etc. Quantitative – measurements. Instruments used: Rulers, balances, stopwatches, etc.

9. Steps of the Scientific Method • 2) Ask a question • 3) Hypothesis • An explanation that is based on prior scientific research or observations and can be tested. • If – then statement.

10. Steps of the Scientific Method 4) Testing the Hypothesis – Experiment A controlledexperiment compares the results from a control group with the results from the experimental groups. The groups are exactly the same except for one factor. That factor is the variable. Independentvariable is the variable you change. Ex. Time Dependentvariable changes in response to the independent variable. Ex. Distance

11. Steps of the Scientific Method 5) Collect, Record, and Analyze Data Data is the information gathered through your experiment. All information needs to be recorded in a notebook, in a data table or other recording devices. Organizing material makes analyzing the data easier.

12. Steps of the Scientific Method • 6) At the end of the investigation, you draw your conclusion. • Accept or reject • Change your hypothesis and retest. • 7) Communicate results • How can you do that?

13. Theory vs. Law A theory is an explanation for many hypotheses and observations. Supported many times. Can predict future results. Can not be proven 100% Examples Big Bang Theory How gravity works A law is a summary of many experimental results and observations. Laws are always true and do not change. Examples Newton’s Laws Conservation of Mass

14. Measurements Length Meters Volume Liters Mass Grams Temperature Kelvin or Celcius Density g/cm3 Time seconds

15. Metric Measurements Prefixes

16. Metric Conversions • K H D __ d c m • 1378 millimeters = ________ dekameters • 45 centimeters = ________ decimeters • 4 liters = ________ hectoliters • 5 kilograms = ________ grams 0.1378 4.5 0.004 5000.

17. Scientific Notation • A way to express very small or very large numbers • Example: • 12345 = 1.2345 x 104 • 0.00456 = 4.56 x 10-3 Exponent – the # of times the decimal was moved (+) to the left (-) to the right Coefficient – must be between 1 and 9 Base

18. Scientific Notation • 56934 = • 1280 = • 0.0345 = • 0.0000037 =

19. Scientific Notation • 2.347 x 10-3 = • 8.98736 x 104 = • 3.48763 x 10-4= • 5.7654 x 105 = Reverse it! (+) right (-) left