Chapter 1 The Nature of Science

I. The Methods of Science A I. The Methods of Science A. Review Vocabulary: Investigation  to observe or study by close examination.

I. The Methods of Science Science means “having knowledge.”

I. The Methods of Science C I. The Methods of Science C. Science → is a process that uses observation and investigation to gain knowledge about events in nature.

I. The Methods of Science D I. The Methods of Science D. There are three major categories of Science: 1. Life science deals with living things. 2. Earth science investigates Earth and space. 3. Physical science deals with matter and energy.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem. 2. Gather information.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem. 2. Gather information. 3. Make a hypothesis.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem. 2. Gather information. 3. Make a hypothesis. 4. Test the hypothesis.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem. 2. Gather information. 3. Make a hypothesis. 4. Test the hypothesis. 5. Analyze the results.

E. Scientific Methods → an organized set of investigation procedures. 1. Identify a problem. 2. Gather information. 3. Make a hypothesis. 4. Test the hypothesis. 5. Analyze the results. 6. Draw conclusions.

F. Hypothesis → a possible solution or an explanation that is consistent with what is known.

G. Experiment → an organized procedure for testing a hypothesis; tests the effect of one thing on another under controlled conditions.

H. Variables → factors that can cause a change in the results of an experiment.

I. Dependent Variable → factor that changes as a result of changes in other variables.

J. Independent Variable → a factor that, as it changes, affects the measure of another variable.

K. Constant → variable that (does, does not) change when other variables change.

Control → standard used for comparison of test results in an experiment.

Bias → occurs when a scientist’s expectations change how the results of an experiment are viewed.

N. How can bias be lessened. 1. By running as many trials as possible N. How can bias be lessened? 1. By running as many trials as possible. 2. By keeping accurate notes.

O. Valid experiments also must have data that are measurable.

P. Most importantly, the experiment must be repeatable.

Q. Model → can be used to represent an idea, object or event that is too big, too small, too complex, or too dangerous to observe or test directly.

R. Scientific Theory → an explanation of things or events that is based on knowledge gained from many observations and investigations.

S. If scientists repeat an investigation and the results always support the hypothesis, the hypothesis can be called a theory.

T. Theories (can, cannot) be modified.

U. Scientific Law → a statement about what happens in nature that seems to be true all the time; does not explain why or how something happens.

Technology → is the application of science to help people.

II. Standards of Measurement A II. Standards of Measurement A. Review Vocabulary: Measurement  the dimensions, capacity, or amount of something.

II. Standards of Measurement B II. Standards of Measurement B. A standard is an exact quantity that people agree to use to compare measurements.

II. Standards of Measurement C II. Standards of Measurement C. Precision → describes how closely measurements are to each other and how carefully the measurements were made.

D. Accuracy → compares a measurement to the real or accepted value.

E. When taking measurements, it is important to be precise and accurate.

F. International System of Units 1 F. International System of Units 1. The system used today by all scientists is called the International System of Units or (SI). 2. Each type of SI measurement has a base unit.

Mars Orbiter Lost – $125 Million Oops. Miscommunication of English vs Mars Orbiter Lost – $125 Million Oops! Miscommunication of English vs. Metric Units.

SI Base Units 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

3. Prefixes are used with the names of the units to indicate what multiple of ten should be used with the units.

Prefixes Prefix Symbol Multiplying Factor Mega- M 1,000,000 kilo- k hecto- h 100 deka- da 10 Base Unit 1

Prefix Symbol Multiplying Factor deci- d 0.1 centi- c 0.01 milli- m 0.001 micro- µ 0.000,001 nano- n 0.000,000,001 pico- p 0.000,000,000,001

Practice: 1. 1 meter = ____ centimeters 2. 1 kilometer = _____meters 3 Practice: 1. 1 meter = ____ centimeters 2. 1 kilometer = _____meters 3. 1 liter = ______ milliliters 4. 1 gram = ______ kilograms 5. 1 decimeter = ______ meters 6. 12 decimeters = ______ meters 7. 54 kilograms = ______ grams 8. 2 liters = ______ hectoliters

G. Measuring Distance 1. Length  is the distance between two points. 2. The SI base unit of length is the meter (m). Why is choosing the correct unit of length important? To avoid large digit numbers and numbers with many decimal places.

H. Measuring Volume 1. Volume  the amount of space occupied by an object. 2. If you want to know the volume of a solid rectangle you would multiply the length, width and height together. 3. If the sides were measured in centimeters, the volume would be expressed in cubic centimeters (cm3).

4. In measuring a liquid’s volume, you are indicating the capacity of the container that is holding the liquid. 5. The most common units for expressing liquid volume are liters (L) and milliliters (mL).

6. One liter occupies the same volume as a cubic decimeter (dm3) 6. One liter occupies the same volume as a cubic decimeter (dm3). {1 L = 1 dm3} 7. Also, important to know is 1 mL = 1 cm3.

I. Measuring Matter 1. Mass  the amount of matter in an object. 2 I. Measuring Matter 1. Mass  the amount of matter in an object. 2. Mass is constant. This means that mass DOES NOT change anywhere you go. 3. (True, False) You have the same mass on Earth as you would on the moon. 4. The standard unit of mass is the kilogram.

5. Weight  is a measure of the gravitational force on an object. 6 5. Weight  is a measure of the gravitational force on an object. 6. Your weight would be different on the moon because the moon has (more, less) gravity. 7. The standard unit of weight is the Newton.

Mass and weight are NOT the same thing!

8. Density  is the mass per unit volume of a material. 9 8. Density  is the mass per unit volume of a material. 9. Density can be found by dividing an object’s mass by its volume. 10. The equation looks like this: D = m/v 11. The standard unit for density is g/cm3.

J. Measuring Time and Temperature 1 J. Measuring Time and Temperature 1. Time  is the interval between two events. 2. The SI unit for time is the second (s).

3. Temperature  is the measure of how hot or cold something is. 4 3. Temperature  is the measure of how hot or cold something is. 4. For most scientific work, temperature is measured on the degree Celsius (°C) temperature scale.

5. The Celsius temperature scale is based on the freezing and boiling point of water. 6. At sea level, pure water freezes at 0 °C and boils at 100 °C.

7. The SI unit of temperature is the Kelvin (K). 8 7. The SI unit of temperature is the Kelvin (K). 8. Zero on the Kelvin scale is the coldest possible temperature, also known as absolute zero. 9. Kelvin temperature can be found by (adding, subtracting) 273 to the Celsius reading. K = °C + 273

Dimensional Analysis A Dimensional Analysis A. This process involves multiplying your starting quantity and units by one or more conversion factors. B. A conversion factor is a ratio equal to one and can be made from any two equal quantities with different units.

Dimensional Analysis C Dimensional Analysis C. Use Table 4 – Unit System Equivalents on page 873 to solve the following problems:

If a meterstick has a length of 100 cm, how long is the meterstick in inches? ? inches = 100 cm 100 cm x 1 inch = 39.37 inches 2.54 cm

2. A book has a mass of 5 lbs. What is the mass of the book in kg 2. A book has a mass of 5 lbs. What is the mass of the book in kg? ? kg = 5 lbs. 5 lbs. x 0.45 kg = 2.25 kg 1 lb.

3. If a bottle of soda contains 2 L, how many gallons would that be equal to? ? gal. = 2 L 2 L x 1 gal. = 0.53 gal. 3.78 L

4. A student weighs 120 lbs. What is their mass in kg. kg = 120 lbs 4. A student weighs 120 lbs. What is their mass in kg? ? kg = 120 lbs. 120 lbs. x 0.45 kg = 54 kg 1 lb.