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Lab Safety Guidelines: What to Wear and Do in the Lab

Learn essential lab safety tips including attire, proper hair styling, equipment handling, and emergency procedures. Watch the video guide for detailed instructions.

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Lab Safety Guidelines: What to Wear and Do in the Lab

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  1. #4 • What should you wear to protect your clothes when in lab? • What should you wear to protect your eyes in lab? • If something breaks what is the FIRST thing you should do? • How should girls wear their hair in lab? • How should your lab station ALWAYS look?

  2. https://www.youtube.com/watch?v=roCQ0WE6zbs&scrlybrkr=cb0dc660https://www.youtube.com/watch?v=roCQ0WE6zbs&scrlybrkr=cb0dc660 1

  3. Nature of Science “Science is a particular way of knowing about the world. In science, explanations are limited to those based on observations and experiments that can be substantiated by other scientists. Explanation that cannot be based on empirical evidence are not part of science.” • The National Academy of Sciences 2

  4. Nature of Science • Science is based on experimentation • The development of an experiment tends to follow the Scientific Method • Ask a question • Conduct background research • Construct a hypothesis • Test your hypothesis in an experiment • Analyze Data • Draw conclusions and communicate them 3

  5. 1. Ask a question – often based on observations • Observation: Description of something you can see, smell, touch, taste, hear • NOT an opinion!! (must be objective) • Example: • The ground is wet • Inference: A guess about an object or outcome based on your observations • You can make many inferences from a single observation • Example: • It rained. • Someone was watering the plants 4

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  7. Ask a question – observations are either… • Qualitative Observation: describes qualities • Examples: • Green liquid • Large hole • Sour taste • Sweet smell • Quantitative Observation: uses numbers to measure something • Examples: • 4 feet long • 6 legs • 7.2 grams • 100 mL 6

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  9. Considerations for Quantitative Data Quantitative data must be… • PRECISE = how close your measurements are to each other (think consistent or specific) • ACCURATE = how close your measurement is to the correct/accepted value (think correct) Always give the most specific reading on your instrument, then estimate one more decimal place 8

  10. Precise and Accurate Precise but not Accurate Accurate but not Precise Not Accurate or Precise 9

  11. Exit Ticket Draw a picture of a target with shots that are both Precise and Accurate.

  12. #1 Use the pictures below to answer the following questions. • List two qualitative observations. • List one quantitative observation. • List two inferences.

  13. 1. Vocabulary word a. Short & Sweet Definition (Not glossary definition) b. Simple Picture c. Use it in a sentence or Simile Can be another tense of the word. Underline word. OR _________ b/c ____________.(justify)

  14. 1. Observation a. Short & Sweet Definition Description of something using senses b. Simple Picture c. Use it in a sentence or Simile I observed that the ground was wet. OR Statement b/c they both involve facts.

  15. Vocabulary Cards

  16. #5 Answer TRUE or FALSE for the following 5 statements. • Safety goggles must be worn at all times while working in the laboratory, even when cleaning up after an experiment. • The fire blanket should be used to smother chemicals that have caught fire. • Hot plates should be turned off whenever not in use, unless they are going to be used again in a minute or two. • It is occasionally permissible to taste substances in the lab to determine their identity. • The teacher should be notified of all chemical spills, unless they are very minor.

  17. 2. Conduct background research – define a Purpose/Objective • The GOAL of scientific investigations is to answer a question • Observations  Questions  Research (what has already been found?)  Purpose • Purpose/Objective is a statement that clearly shows what question you are trying to answer in your investigation 10

  18. 3. Construct a Hypothesis • Hypothesis: A testable prediction based on observations (more than a guess!!) that describes a cause and effect relationship between variables Format for a Hypothesis: “IF (IV) then (DV) “ IV = Independent variable = Cause DV = Dependent variable = Effect 11

  19. Defining Independentand DependentVariables • Independent Variable: (IV) what the experimenter will deliberately change or manipulate in the investigation • The X-Axis on a graph • It is the ONLY thing different between different experimental groups • Ex. You want to do an experiment to see if what you drink before a race affects how quickly you run. • What is the IV? 12

  20. DefiningIndependentand Dependent Variables • Dependent Variable: (DV) what changes in response to the independent variable • The Y-Axis on a graph • Usually represented by the data you collect in an investigation; what is measured • Ex. Recall the running experiment. • What is the DV? 13

  21. Individual Practice Get out p 8: Understanding Hypothesis • Homework if not finished • Work on Vocab cards when finished.

  22. 1. Observation a. Short & Sweet Definition Description of something using senses b. Simple Picture c. Use it in a sentence or Simile I observed that the ground was wet. OR Statement b/c they both involve facts.

  23. Exit Ticket Which variable does the experimenter change in a scientific investigation?

  24. #6 • What is the best glassware for performing small chemical reactions? • What is the best glassware for measuring? • What is a petri dish used for? • In a graduated cylinder, what is the bottom of the curve in the liquid called that you are supposed to measure to? • What type of shoes are best to wear during lab?

  25. 4. Test your hypothesis in an experiment- Materials • What will you need to conduct the experiment? • Include amounts • Include brands, if important • Be as specific as possible! • Write as a bulleted list 14

  26. Test your hypothesis in an experiment- Procedures • Write out every step that was taken • Start with an action word • Include every step so that someone could replicate the experiment • Make this a numbered list When designing experimental procedures you must ALWAYS consider… • Experimental Group: groups that are being tested • What is the experimental group in the running example? 15

  27. When designing experimental procedures you must ALWAYS consider… • Control Group: group used for comparison with your experimental groups. This is the “normal” group • What is the control group in the running example? • Constants: the aspects of an experiment that are held constant/consistent • Ensures that all aspects of trials are identical, except for the IV • Ensures that any difference measured in the DV is caused only by the IV • Ex. All runners should be the same age, gender, same breakfast, same training, same shoes, etc. 16

  28. When designing experimental procedures you must ALWAYS consider… Repeated Trials to: • Ensure the results aren’t due to chance • Eliminate any errors • Ensure the data is precise 17

  29. Individual Practice Get out p 9: Understanding Hypothesis • Homework if not finished • Work on Vocab cards when finished.

  30. Exit Ticket Something that stays the same between experimental groups and control groups is called a ________.

  31. #7 1. What is the independent variable in the hypothesis below? • If a student attends afterschool tutoring, then they will score higher on their test than students who do not attend tutoring. 2. What is the dependent variable in the hypothesis above? 3. Write a hypothesis using these IV and DV • IV = Different amounts of fertilizer • DV = Plant growth

  32. Exit Ticket Why is it important to have constants between groups in today’s experiment?

  33. #8 • I want to design an experiment to see if drinking coffee makes students score higher on tests. • What is the independent variable in this experiment? • What is the dependent variable in this experiment? • What would be the control groupin this experiment? • 4. What would be the experimental group in this experiment? • 5. List a necessary constant.

  34. 5. Analyze Data – Results and Analysis Results • Collect data in an organized form during an investigation (ex. Data Table) • Present data in a graph Analysis • Only make statements about what the data shows • Do NOT state in analysis whether your hypothesis was “right” or “wrong” • Include any errors you made

  35. 6. Draw conclusionsand communicate them • Make an explicit statement about whether your hypothesis was supported or rejected by your experimental data • Data may support your prediction • Data may fail to support (reject) your prediction • NOTE: Data does NOT prove/disprove • State the real world application.

  36. Individual Practice Get out p 12, 13:

  37. Exit Ticket On which axis do you plot the independent variable?

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