Unit 1 The Nature of Science

Unit 1 Learning Targets By the end of this unit you should be able to: –Discuss science and its major branches –Explain and identify the steps of the scientific method –Compare and contrast independent and dependent variables –Understand controls and constants –Identify scientific theory and scientific laws –Be able to convert between SI Units –Read, construct and analyze graphs from provided data

Learning Targets, continued Define the following: –Scientific method –Hypothesis –Experiment –Variable –Dependent variable –Independent variable –Constant –Control –Bias –Theory –Scientific law

Chapter 1 Section 1 What is Science –Using observations and investigation to gain knowledge Major categories –Life –Earth –Physical Science explains Nature –Science explanations help us understand our natural world Investigations – Investigations or science experiments, help us learn more about our world

Scientific Method –A step by step set of procedures scientists use to figure out questions –Steps Problem –Always a question –Why or How Research/Gathering Information –Learn as much about the problem as possible –Use what you have learned to write your hypothesis

Hypothesis –A guess based on the background information you have about the question –A possible explanation –Generally stated »“if……….then….” OR »“I think…….because…..”

Record/Analyzing your data/observations –Data = numbers –Observations = using your senses to determine what is happening –Record everything –Do not ever change you results (EVEN IF THEY ARE WRONG!!!) –Use charts, data tables, compete observations Draw conclusions –Based on the data and observations –Determine if your hypothesis was supported or not supported –Explain possible reasons for errors Being objective –Remove any bias by running experiment at least 3 times –Experiment MUST be repeatable

Visualizing with Models –Helps people understand an idea, event or object more clearly Scientific Theories and Laws –Theory Explanation based on observations from many many experiments Investigation can be reproduced with the same results time and time again!!! –Law Explains what happens in nature and happens all the time Don’t explain WHY it happened just that it DID

Chapter 1 Section 2 Standards of Measurement –Standard = agreed upon by everyone –Science uses International System of Units New form of the metric system Uses base units –Meter = length –Gram = mass –Liter = volume –Second = time –Kelvin = temperature –Mole = Amount of a substance

SI Prefix –Kilo = 1,000 –Hecto = 100 –Deka = 10 –Base = 1 –Deci =.1 –Centi =.01 –Milli =.001 –Micro = –Nano =

–Converting between SI Units

–Measuring Distance measurement between two points Unit = meters Instrument = meter stick

Measuring Volume –The amount of space an object takes up Regularly shaped objects –L x w x h –Units = cm3, m3, etc –Instrument = meter stick Irregularly shaped objects –Water displacement –Instrument = graduated cylinder, dunk tank –Units = mL, L, etc 1mL = 1 cm3

Measuring Matter –Mass Amount of matter in an object Unit = grams Instrument = triple beam balance

Density –Amount of matter (mass) in a specific area (volume) –Equation = mass divided by volume –Units = g/mL or g/cm3 –Tells us if something sinks or floats –MORE than 1.0 g/mL = object sinks –LESS than 1.0 g/mL = object floats

Measuring Time and Temperature –Time = interval between two events –What is Hot and What’s not Temp = how hot or cold something is Three scales, Celsius, Fahrenheit, and Kelvin Water freezes = 0 C and 273 K Water boils = 100 C and 373 K Kelvin = C + 273

Chapter 1 Section 3 A visual display –Line Graphs Show relationships between changing variables Independent variable goes on the X Dependent variable goes on the Y

–Bar Used for comparing information Independent variable goes on the X Dependent variable goes on the Y

–Pie graph Shows quantity broken into parts Often shows percentages