Chapter 1 The Nature of Science Physical Science Chapter 1 The Nature of Science

The Methods of Science What is Science? Major Categories of Science Science is a process that uses observation and investigation to gain knowledge about events in nature. Major Categories of Science Life Science Earth Science Physical Science

Investigations How do scientists learn more about the natural world? By performing investigations. Observation Experiments Building a model or simulation

Scientific Method Organized set of investigation procedures. 6 steps Stating the problem Researching and Gathering Information Forming a Hypothesis Testing a Hypothesis Analyze the Data Draw a Conclusion

Forming a Hypothesis Hypothesis An educated guess based on what you know and what you observe.

Testing the Hypothesis Hypothesis can be tested by observation or an experiment. Experiment tests the effect of one thing on another under controlled conditions.

Experiment Variable—is a factor that can cause a change in the results of an experiment. Experiment usually contains at least 2 variables. Dependent variable—a factor that changes according to changes in the other variables. Independent variable—factor that as it changes effects the measure of another variable. Experiment usually contains at least 2 variables.

Experiment cont’ Constant—a variable that does not change when other variables change. Control—standard used for comparison of test results in an experiment.

Draw Conclusion Based on the analysis of your data, you decide whether your hypothesis is supported or unsupported. If hypothesis is unsupported by you data, you must reconsider your hypothesis and possibly revise it also.

Being Objective Objective—existing independently of perception or an individual’s emotion/personal bias. Bias—occurs when a scientist’s expectations change how the results of an experiment are viewed.

Scientific Theories and Law Scientific Theory—is an explanation of things or events based on knowledge gained from many observations and investigations. Scientific Law—is a statement about how things work in nature and that seems to be true all the time. Example: Gravity.

Technology Technology—is the application of science to help people. What is an example of technology used in science?

Standards of Measurement Standard—exact quantity used for comparison. International System of Units (SI) standards—universally accepted and understood by scientists throughout the world.

International System of Units Each type of SI measurement has a base unit… Quantity Measured Unit Symbol Length meter m Mass kilogram kg Time second s Electric Current ampere A Temperature kelvin K Amount of Substance mole mol Intensity of Light candela cd

Base Units Length—straight-line distance between two points. meter (m) Mass—the quantity of matter in an object or sample. kilogram (kg)

Derived Units Derived Units—made from combinations of base units. Volume—amount of space taken up by an object. Cubic meter Density—is the ratio of an object’s mass to its volume Density= mass volume

SI Prefixes Common SI Prefixes Prefix Symbol Multiplying Factor Kilo- 1,000 Deci- d 0.1 Centi- c 0.01 Milli- m 0.001 Micro- µ 0.000 0001 Nano- n 0.000 000 001

Converting Between SI Units

Limits of Measurement Precision—a gauge of how exact a measurement is Significant figures—are all the digits that are known in a measurement , plus the last digit that is estimated. Accuracy—closeness of a measurement to the actual value of what is being measured.

Measuring Temperature What do instrument do you use to measure temperature? Thermometer 3 different scales for temperature Fahrenheit Celsius Kelvin

Converting Temperature Formulas

1. 212ºF= ______ ºC 2. 20ºC = ______ ºF 3. 98.6ºF = _______ K

Assignment Pg 28 & 29 Write Vocab 1.2 1.3 Reviewing Content #’s 1-4