Slide 1 of 21 Chapter Scientific Method Mrs. Baldessari Chemistry Objective : Identify and apply the steps of the scientific method. 1

Slide 2 of 21 – The goal of science is to: investigate and understand the natural world. explain events in the natural world. use those explanations to make useful predictions. What is the goal of science? 1

Slide 3 of 21 Thinking Like a Scientist Scientific thinking begins with observation. Observation is the process of gathering information about events or processes in a careful, orderly way Use your senses to observe – See, hear, touch, taste, smell, etc. Can also use tools to measure – Temperature, length, volume, etc. 1

Slide 4 of 21 4 What are the steps of the scientific method? 1.Define the problem a.Select an event or phenomenon for investigation. b.The problem is often based on some type of unexplainable observation. c.The problem is usually stated as a question to be answered.

Slide 5 of 21 5 What are the steps of the scientific method? 2.Gather relevant research a.The researcher gathers useful information from scientific literature. b.Observations of the problem may also contribute to research.

Slide 6 of 21 6 What are the steps of the scientific method? 3.Formulate a hypothesis A hypothesis is an “educated guess” about the answer to the problem. The hypothesis is based on information, which has been learned about the problem through research. May be stated as an “If…., then…” statement A hypothesis may be ruled out or confirmed.

Slide 7 of 21 7 What are the steps of the scientific method? 4.Test the hypothesis A hypothesis must be proposed in a way that can be tested. Hypotheses are tested by performing controlled experiments or by gathering new data. Remember, controlled experiments are experiments that only have one variable that can change, all other factors are held constant

Slide 8 of 21 8 What are the steps of the scientific method? 5. Record data and observations The information gathered from observations is called data. Quantitative data are expressed as numbers, obtained by counting or measuring. Qualitative data are descriptive and involve characteristics that can’t easily be measured.

Slide 9 of 21 Look around the room list Five Quantitative observations:

Slide 10 of 21 1 Look around the room list Five Qualitative observations:

Slide 11 of 21 Inferences Scientists use data to make inferences. An inference is a logical interpretation based on prior knowledge or experience. Is this an observation or inference? 1. Sam is smiling because he is happy 2. Sarah’s gold colored braces were removed today 1

Slide 12 of 21 You try: Observation or inference? Object A is round Object A is a basketball Object C is round and black and white Object C is larger than object B Object B is smooth Object B is a ping-pong ball Each object is used in a different sport 1

Slide 13 of 21 Observation or inference Object A is round Object A is a basketball Object C is round and black and white Object C is larger than object B Object B is smooth Object B is a ping-pong ball Each object is used in a different sport A is a basketball; B is a ping-pong ball; C is a soccer ball OI x x x x x x xx 1

Slide 14 of 21 Designing an Experiment with Twinkies Discussion of independent variables and control variables 1

Slide 15 of 21 What is the control? What is the independent variable? 1

Slide 16 of 21 Control Is an experimental set-up with all the parts of the experiment BUT NOT the one variable being tested 1

Slide 17 of 21 What is the independent variable? What might a control be? 1

Slide 18 of 21 What is the independent variable? What might a control be? 1

Slide 19 of 21 Identify Variable and the control: 19

Slide 20 of 21 To get all the air out, the twinkie was “liquified.” So which side is the control? 1

Slide 21 of What are the steps of the scientific method? 6.Draw conclusions Researchers often work in teams to analyze, review, and critique each other’s data and hypotheses. A review process helps ensure conclusions are valid. To be valid, a conclusion must be based on logical interpretation of reliable data. Always address sources of error…are your results legitimate? Theories and laws are heavily supported by experimental results

Slide 22 of 21 Copyright © by McDougal Littell. All rights reserved. 22 Figure1.1: The various parts of the scientific method.

Slide 23 of 21 Science is an ongoing process that involves: – asking questions – observing – making inferences – testing hypotheses 1

Slide 24 of 21 State the Question “What is the effect of…” 24

Slide 25 of 21 Hypothesis “If…then…” If I diligently wear my goggles in the lab, then I will not injure my eyes during Chemistry class this year. 1

Slide 26 of 21 Experiment Independent Variable -what you change goes on the X-axis of the graph Dependent Variable -what changes as a result of what you did – goes on the Y-axis of the graph 1

Slide 27 of 21 Independent Variable? Dependent Variable? 1

Slide 28 of 21 Experiment Constants-all the things in the experiment that stay the same In a Twinkie lab : same brand of Twinkies same flavor of Twinkies same degree of freshness 1

Slide 29 of 21 Experiment Control – the part of the experiment that does not have the independent variable in it In a Twinkie lab, it could be the room temperature 29

Slide 30 of 21 Experiment Record the data graphs charts video write observations measurements 30

Slide 31 of 21 Conclusion Agree or disagree with the hypothesis Goggles did protect my eyes during an accident 31

Slide 32 of 21 Scientific method Do background Research Record Results Analyze Results Draw a conclusion Present results State your question or the problem Formulate a hypothesis, identify variables Design a Controlled Experiment, establish a procedure 1

Slide 33 of 21 Science as a Way of Knowing Scientific understanding is always changing. Good scientists are skeptics who question both existing ideas and new hypotheses. 1

Slide 34 of 21 1–1 Observations involving numbers are known as a.qualitative observations. b.hypothetical observations. c.quantitative observations. d.inferred observations. 1

Slide 35 of 21 1–1 A scientist takes paint chips from 10 apartments in a large building. She tests for the presence of lead in the paint and finds it in all 10 samples. She then concludes that lead paint is probably present in all 120 apartments in the building. This conclusion is an example of a.a scientific fact. b.a scientific error. c.proof. d.a reasonable inference. 1

Slide 36 of 21 1–1 A possible explanation for a set of observations is known as a.data. b.a hypothesis. c.an inference. d.a result. 1

Slide 37 of 21 1–1 A good scientific hypothesis must be a.correct. b.able to be tested. c.obvious. d.based on common sense. 1