Presentation on theme: "Chapter 1: Nature of Science"— Presentation transcript:
1 Chapter 1: Nature of Science What is a scientist and what does he do?Scientists investigateScientists plan experimentsScientists observeScientists test resultsSCIENTISTS ASK GOOD QUESTIONS!
2 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.
3 Scientific TheoryA 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.
4 Scientific LawA scientific law is a description of a natural event. [Laws have been proven]Newton’s law of gravityNewton’s laws of motionHooke’s lawKepler’s laws of planetary motionEtc.
5 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?
6 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)
7 Scientific Method [5 steps] Make an observationForm an hypothesisMake predictionsTest the hypothesisDraw a conclusion
8 Systeme International d' Unites – SI Measurement System Base Units of SI System (total of 7)Length – Meter, mMass – Kilogram, kgTime – Second, sTemperature – Kelvin, KElectric current – ampere, AAmount of substance – mole, molLuminous intensity – candela, cd
9 Systeme International d' Unites – SI Measurement System Derived Units of SI System (hundreds)Force – Newton, NArea – Square meters, m2Volume (liquid)– Liter, L.Velocity – meters/second, m/sAcceleration - meters/second/second, m/s2Pressure- N/m2
10 Examples of SI Measurement System units Length – meter, mForce or weight – Newton, NMass – kilogram, kgArea – m2Volume – m3Density – g/cm3Time – second, sTemperature – degrees Celsius, oC
11 Examples of English Measurement System units Length – feet, ftForce or weight – pounds, lbsArea – square feet, ft2Volume – cubic feet, ft3Density – pound per cubic feet, lb/ft3Time – seconds, sTemperature – degrees Fahrenheit, oFEtc.
12 Scientific NotationIn 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 10-6422,000,000,000,000 = x 1014
13 Significant FiguresFor 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.
14 Scientific NotationScientific Notation: a value written as a simple number multiplied by a power of 10.Ex: = = 10-3Why is one positive and the other negative?Very large #’s are positive and very small #’s are negative.
15 Metric Prefixes Prefix Symbol Meaning kilo- k 1000 hecto- h 100 deka- da 10Base Unitdeci- d 0.1centi- c 0.01milli- mmicro- mnano- n
16 Meaningful Metric Prefixes Prefix Symbol Meaningtera- T or 1012giga- G or 109mega- M or 106kilo- k or 103milli- m or 10-3micro- m or 10-6nano- n or 10-9pico- p or 10-12
17 Converting temperature Conversion of Fahrenheit to CelsiusoC = 5/9 [oF ]Conversion of Celsius to FahrenheitoF = [9/5 x oC]
18 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 cmEx: How many
19 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.
20 Conversion Factor Process Ex: Write 550 millimeters as meters#1: given: 550 millimeters#2: looking for meters#3: want to cancel millimeters550 mm x 1 m/1000 mmCalculate: 550 x 1 / 1000 = 0.55 m
21 Conversion Practice Convert the following: 1.6 kilograms to grams 2500 milligrams to kilograms0.4 millimeters to micrometers2800 millimoles to moles6.1 amperes to milliamperes1600 g.0025 Kg400 mm2.8 mol6100 mA
22 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 = metersMass = gramsVolume = liters or cubic centimeters cm3
23 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.
24 Graphs There are several types of graphs. Line graph: shows change over timeBar graph: good for comparing data for several individual items or eventsPie chart: ideal for displaying data that are parts of a whole
25 Line GraphIndependent 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.
26 Bar GraphWhat you’re comparing goes on the x axis