1. Methods of Scientists Section 1.2

2. The Nature of Scientific Investigation Scientific method – a series of problem solving procedures that help scientists conduct experiments Hypothesis – a testable explanation of a situation that can be supported or disproved by careful procedures

3. Experimentation Experiment – a procedure that involves making observations and measurements to test a hypothesis Independent variable - the factor changed by the experimenter Dependent variable – a factor that is affected by changes in the independent variable Control – used to show that results are a result of the condition being tested

4. Investigation How does an experiment and an investigation differ? Investigations do not involve a control

5. Analysis and Conclusions What is bias? Data can be displayed using graphs, tables, or charts What happens when a conclusion does not support the hypothesis?

6. Measurement Experiments and investigations involve taking measurements Measurements include a number and units The standard system of units used by scientists are called SI units SI units are based on a decimal system that uses the number 10 as the base unit

7. SI Units Write the correct SI unit for each of the following: Length Mass Area Volume Density Time Temperature

8. Mass vs. Weight How does mass and weight differ? Weight depends upon gravity Your mass on the moon and mass on Earth are the same. However, your weight would differ.

9. Scientific Notation Use scientific notation to express the following: Speed of light: 299,792,458 m/s Mass of an electron: 0.000000000000000000000000000000911 kg