# Chapter 1: Nature of Science

## Presentation on theme: "Chapter 1: Nature of Science"— Presentation transcript:

Chapter 1: Nature of Science
What is a scientist and what does he do? Scientists investigate Scientists plan experiments Scientists observe Scientists test results SCIENTISTS ASK GOOD QUESTIONS!

Pure Science vs. Technology
Pure Science is scientific knowledge gained by observation and experiment. Technology is the application of pure science to meet human needs.

Scientific Theory A scientific theory is a tested, explanation of a natural event. [Theories have not been proven] A theory must explain observations simply and clearly. Experiments that illustrate the theory must be repeatable. You must be able to predict from the theory.

Scientific Law A scientific law is a description of a natural event. [Laws have been proven] Newton’s law of gravity Newton’s laws of motion Hooke’s law Kepler’s laws of planetary motion Etc.

Section 1.1 Review: Explain how science and technology depend on each other. How does a scientific law differ from a theory? Pick a common phenomenon and develop a theory about it, what kind of experiment could you do to test the theory?

Section 1.2 The Way Science Works
Critical thinking is a basic skill of a scientist. It is applying logic and reason to observations and conclusions. The scientific method is a series of logical steps to follow in order to solve a problem or answer a question. (pg. 13 fig 1-12)

Scientific Method [5 steps]
Make an observation Form an hypothesis Make predictions Test the hypothesis Draw a conclusion

Systeme International d' Unites – SI Measurement System
Base Units of SI System (total of 7) Length – Meter, m Mass – Kilogram, kg Time – Second, s Temperature – Kelvin, K Electric current – ampere, A Amount of substance – mole, mol Luminous intensity – candela, cd

Systeme International d' Unites – SI Measurement System
Derived Units of SI System (hundreds) Force – Newton, N Area – Square meters, m2 Volume (liquid)– Liter, L. Velocity – meters/second, m/s Acceleration - meters/second/second, m/s2 Pressure- N/m2

Examples of SI Measurement System units
Length – meter, m Force or weight – Newton, N Mass – kilogram, kg Area – m2 Volume – m3 Density – g/cm3 Time – second, s Temperature – degrees Celsius, oC

Examples of English Measurement System units
Length – feet, ft Force or weight – pounds, lbs Area – square feet, ft2 Volume – cubic feet, ft3 Density – pound per cubic feet, lb/ft3 Time – seconds, s Temperature – degrees Fahrenheit, oF Etc.

Scientific Notation In many branches of science, some numbers are very small, while others are quite large. To conveniently express these numbers, scientists use a type of shorthand called scientific notation to express the number as a multiplier and a power of 10. = x 10-6 422,000,000,000,000 = x 1014

Significant Figures For numbers with no decimal point, start from the “atlantic” right hand side and count all digits beginning with the first non-zero digit. Ex: has two sig. figs. For numbers with a decimal point, start from the “pacific” left hand side and count all digits beginning with the first non-zero digit.

Scientific Notation Scientific Notation: a value written as a simple number multiplied by a power of 10. Ex: = = 10-3 Why is one positive and the other negative? Very large #’s are positive and very small #’s are negative.

Metric Prefixes Prefix Symbol Meaning kilo- k 1000 hecto- h 100
deka- da 10 Base Unit deci- d 0.1 centi- c 0.01 milli- m micro- m nano- n

Meaningful Metric Prefixes
Prefix Symbol Meaning tera- T or 1012 giga- G or 109 mega- M or 106 kilo- k or 103 milli- m or 10-3 micro- m or 10-6 nano- n or 10-9 pico- p or 10-12

Converting temperature
Conversion of Fahrenheit to Celsius oC = 5/9 [oF ] Conversion of Celsius to Fahrenheit oF = [9/5 x oC]

Section 1.2 cont.. A conversion factor is used to convert between units. Ex: How many centimeters are in 1.85 inches? 1.85 in x [2.54 cm/1 in] 4.70 cm Ex: How many

Section 1.2 cont… How to set up a conversion factor:
#1: Always write what you are given FIRST! #2: Put what you are looking for on top of the conversion line. #3: Put what you are trying to cancel out on the bottom of the conversion line.

Conversion Factor Process
Ex: Write 550 millimeters as meters #1: given: 550 millimeters #2: looking for meters #3: want to cancel millimeters 550 mm x 1 m/1000 mm Calculate: 550 x 1 / 1000 = 0.55 m

Conversion Practice Convert the following: 1.6 kilograms to grams
2500 milligrams to kilograms 0.4 millimeters to micrometers 2800 millimoles to moles 6.1 amperes to milliamperes 1600 g .0025 Kg 400 mm 2.8 mol 6100 mA

Section 1.2 Making Measurements
There are many observations that rely on quantative measurements. The most basic scientific measurements generally answer how big, how much, or how much time. We use length, mass, time, and volume as quantative measurements in labs. Remember: Length = meters Mass = grams Volume = liters or cubic centimeters cm3

Organizing Data There are several ways to organize lab data.
Data Chart: Good way of keeping track of something over time or making several readings on a topic. Usually done as raw data. Graphs: A good way to organize your raw data and show trends, inferences, or results.

Graphs There are several types of graphs.
Line graph: shows change over time Bar graph: good for comparing data for several individual items or events Pie chart: ideal for displaying data that are parts of a whole

Line Graph Independent variable: goes on the x axis. That is the bottom of the graph. Here the time in days is the independent variable. This variable is determined by the experimenter. Dependent variable: what is changing in the experiment. This is not determined by the experimenter.

Bar Graph What you’re comparing goes on the x axis

Pie Chart

Download ppt "Chapter 1: Nature of Science"

Similar presentations