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Lab Safety Discuss with your table: Discuss with your table: 5 Things you should not do in a laboratory. 5 Things you should not do in a laboratory. 5.

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Presentation on theme: "Lab Safety Discuss with your table: Discuss with your table: 5 Things you should not do in a laboratory. 5 Things you should not do in a laboratory. 5."— Presentation transcript:

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2 Lab Safety Discuss with your table: Discuss with your table: 5 Things you should not do in a laboratory. 5 Things you should not do in a laboratory. 5 Safety rules you should follow in a laboratory. 5 Safety rules you should follow in a laboratory.

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4 http://www.teachertube.com/me mbers/viewVideo.php?title=lab_ safety&video_id=5987

5 What is Science??

6 What is Science? Science is an organized way of using evidence to learn about the natural world Science is an organized way of using evidence to learn about the natural world

7 What is the goal of Science? The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions

8 How does a person “think” like a scientist A car won’t start…………. A car won’t start…………. Why? Why?

9 Observations Scientific thinking usually begins with observations. Scientific thinking usually begins with observations. Observation- the process of gathering information about events or processes in a careful, orderly way. Observation- the process of gathering information about events or processes in a careful, orderly way. Observations are made using senses such as sight and sound. Observations are made using senses such as sight and sound.

10 Inference The car wont start because it needs gas The car wont start because it needs gas Definition: a logical interpretation based on prior knowledge or experience. In other words recalling facts and details of past experiences. After taking many water samples from Coney Island Beach the scientist can INFER that that the water is clean.

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12 Soda Can Regular SodaDiet Soda Regular SodaDiet Soda

13 The Scientific Method : Designing an Experiment : Designing an Experiment Asking a question Asking a question Forming a hypothesis Forming a hypothesis Setting up a controlled experiment Setting up a controlled experiment Recording and analyzing results Recording and analyzing results Drawing a conclusion Drawing a conclusion

14 People contract an unknown disease after attending a Justin Timberlake concert People contract an unknown disease after attending a Justin Timberlake concert To understand why these people became ill, Public health researchers will follow the scientific method To understand why these people became ill, Public health researchers will follow the scientific method

15 Ask a Question Why did so many people get sick? Why did so many people get sick? Is this sickness related to something at the concert or is it a coincidence? Is this sickness related to something at the concert or is it a coincidence? What type of sickness is this, how is it spread? What type of sickness is this, how is it spread?

16 Hypotheses Since this illness is unknown there might be a couple of different hypotheses Since this illness is unknown there might be a couple of different hypotheses 1. The disease was spread from person to person 1. The disease was spread from person to person 2. The disease was spread by insect bites 2. The disease was spread by insect bites 3. The disease was spread by food. 3. The disease was spread by food.

17 Hypothesis After initial observations, the researchers will propose one or more hypotheses. After initial observations, the researchers will propose one or more hypotheses. Definition: proposed scientific explanation for a set of observations. Definition: proposed scientific explanation for a set of observations. Scientists form hypotheses by using prior knowledge or what they already know (inference) Scientists form hypotheses by using prior knowledge or what they already know (inference) Experiments can only support a hypothesis or fail to support a hypothesis. Experiments can only support a hypothesis or fail to support a hypothesis.

18 Hypotheses are tested by collecting more data or performing controlled experiments (to be explained later). Hypotheses are tested by collecting more data or performing controlled experiments (to be explained later). How would you collect more data in this situation? How would you collect more data in this situation?

19 Ask a Question: Ask a Question: The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where? The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where? Do Background Research: Do Background Research: use the internet or other resources to research your question before you construct a hypothesis use the internet or other resources to research your question before you construct a hypothesis Construct a Hypothesis: A hypothesis is an educated guess about how things work: "If _____[I do this] _____, then _____[this]_____ will happen." You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question. Construct a Hypothesis: A hypothesis is an educated guess about how things work: "If _____[I do this] _____, then _____[this]_____ will happen." You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.

20 Test Your Hypothesis by Doing an Experiment: Test Your Hypothesis by Doing an Experiment: Your experiment tests whether your hypothesis is true or false. Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident.

21 Collect Data Experiments/Research is done in order to collect organized data.

22 Analyze Your Data and Draw a Conclusion: Once your experiment is complete, you collect your measurements and analyze them to see if your hypothesis is true or false. Data: refers to the results of the tests completed during the experiment

23 Communicate your data After completing an experiment that supports a scientists hypothesis, scientist submit their experimental data to PEER REVIEW After completing an experiment that supports a scientists hypothesis, scientist submit their experimental data to PEER REVIEW Peer Review- system of checks and balances in science

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25 Data Data is the information gathered from observations. Data is the information gathered from observations. There are two different forms of data There are two different forms of data

26 Quantitative data Data expressed as numbers from measurements or counting Data expressed as numbers from measurements or counting

27 Qualitative Data Data that is descriptive and usually can not be counted (does not involve numbers) Data that is descriptive and usually can not be counted (does not involve numbers) “the animal seems healthy and alert” “the animal seems healthy and alert” “the car won’t start” “the car won’t start” Scientists use data to make inferences Scientists use data to make inferences

28 Key Terms The dependent variable (responding variable) is the variable that is being tested and that changes in response to the independent variable. The dependent variable (responding variable) is the variable that is being tested and that changes in response to the independent variable. The independent variable (manipulated variable) is the variable that is deliberately changed. The independent variable (manipulated variable) is the variable that is deliberately changed. A control is a reference point in which you will be comparing your experimental results. A control is a reference point in which you will be comparing your experimental results.

29 Independent variables answer the question "What do I change?" Dependent variables answer the question "What do I observe?" Controlled variables answer the question "What do I keep the same?"

30 Identify the Controls and Variables Identify the Controls and Variables Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks. Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks. Identify the: Identify the: 1. Control Group 1. Control Group 2. Independent Variable 2. Independent Variable 3. Dependent Variable 3. Dependent Variable 4. What should Smithers' conclusion be? 4. What should Smithers' conclusion be? 5. How could this experiment be improved? 5. How could this experiment be improved?

31 Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower. Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower. 6. What was the initial observation? Identify the- 7. Control Group 6. What was the initial observation? Identify the- 7. Control Group 8. Independent Variable 8. Independent Variable 9. Dependent Variable 9. Dependent Variable 10. What should Homer's conclusion be? 10. What should Homer's conclusion be?

32 Bart believes that mice exposed to microwaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same. Bart believes that mice exposed to microwaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same. Identify the- 11. Control Group Identify the- 11. Control Group 12. Independent Variable 12. Independent Variable 13. Dependent Variable 13. Dependent Variable 14. What should Bart's conclusion be? 14. What should Bart's conclusion be? 15. How could Bart's experiment be improved? 15. How could Bart's experiment be improved?

33 Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes. Identify the- 16. Control Group Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes. Identify the- 16. Control Group 17. Independent Variable 17. Independent Variable 18. Dependent Variable 18. Dependent Variable 19. Explain whether the data supports the advertisements claims about its product 19. Explain whether the data supports the advertisements claims about its product

34 Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment. Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment. 20. Describe how Lisa would perform this experiment. Identify the control group, and the independent and dependent variables in your description. 20. Describe how Lisa would perform this experiment. Identify the control group, and the independent and dependent variables in your description.

35 Which is the dependent variable, independent variable, and control?? In 1668, Francesco Redi, an Italian physician, did an experiment with flies and wide-mouth jars containing meat. This was a true scientific experiment — many people say this was the first real experiment — containing the following elements:

36 Experiment to prove or disprove Spontaneous Generation Observation: There are flies around meat carcasses at the butcher shop. Observation: There are flies around meat carcasses at the butcher shop. Question: Where do the flies come from? Does rotting meat turn into or produce the flies? Question: Where do the flies come from? Does rotting meat turn into or produce the flies? Hypothesis: Hypothesis: Prediction: Prediction: Testing: Testing: Data: Data: Conclusion(s): Conclusion(s):

37 Models in Science A model: is any representation of an object or an event used as a tool for understanding the natural world. A model: is any representation of an object or an event used as a tool for understanding the natural world. They can help you visualize (picture in your mind) something that could be hard to understand. They can help you visualize (picture in your mind) something that could be hard to understand.

38 Types of Models Physical models- models that you can see and touch Physical models- models that you can see and touch Computer models- you can’t touch them but you can view them on the computer. Computer models- you can’t touch them but you can view them on the computer.

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40 Idea models: models that are ideas or concepts such as Einstein’s E=mc2 (this can never be a physical model) But mathematically describes the relationship between matter and energy. Idea models: models that are ideas or concepts such as Einstein’s E=mc2 (this can never be a physical model) But mathematically describes the relationship between matter and energy.

41 Examples of models Maps, drawings, recipes, globes, computer weather map (on TV) Maps, drawings, recipes, globes, computer weather map (on TV) Crash test dummies Crash test dummies Dinosaurs in museums Dinosaurs in museums

42 Instead of writing out what the mummy of King Tut looked like you would use a model

43 Models Test predictions Wind tunnels are used Wind tunnels are used Simulated cities with flooding Simulated cities with flooding Models save lives-easier to test a model than a person- crash test dummies Models save lives-easier to test a model than a person- crash test dummies

44 Models aren’t always right Just like a hypothesis! They can be tested as true and thought of as a Scientific Theory. Just like a hypothesis! They can be tested as true and thought of as a Scientific Theory. But before becoming a scientific Law But before becoming a scientific Law (a theory tested many times) (a theory tested many times) But with advances in technology, models can also be proven wrong (just like a hypothesis)

45 People used to think that the earth was at the center of the solar system. People used to think that the earth was at the center of the solar system. Silly right? Silly right? Later on, we found out that it is really the sun!!, so the first model ended up being wrong. Later on, we found out that it is really the sun!!, so the first model ended up being wrong.

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