Unit 1 Safety and Scientific Foundation PLC-Unit 1 1

Section I Safety PLC-Unit 1

PLC-Unit 1

Safety Features of the Lab Safety shower Fire blanket Fire extinguisher (2) Eye wash Fume hood PLC-Unit 1

Safety in the Classroom Obey the safety contract Use common sense No unauthorized experiments Wear safety glasses and apron Safety is an attitude! Don’t take anything out of lab Read and follow all instructions Go over Safety Contract with students. Link for copy of safety contract: http://www.unit5.org/chemistry/christjs/2safetycontract.doc PLC-Unit 1

I'm a little Chemist, short and stout, Here are my goggles, here are my eyes. When I don't wear my goggles, my teacher shouts, PUT THEM ON OR YOU GET OUT! Anyone caught not wearing their goggles (teacher included) must sing a goggle song for the whole class. If you feel this is too embarrassing, have the whole class sing the song anytime one of them is caught. Here's an example of a song sung to the tune of "I'm a Little Teapot." I'm a little Chemist, short and stout, Here are my goggles, here are my eyes. When I don't wear my goggles, my teacher shouts, PUT THEM ON OR YOU GET OUT! PLC-Unit 1

Wear Your Safety Goggles! Which would you rather read? PLC-Unit 1

Material Safety Data Sheet (MSDS) Gives information about a chemical. Lists “Dos” and “Don’ts.” PLC-Unit 1

MSDS Sheet PLC-Unit 1

FRHSD Safety Contract PLC-Unit 1 FLINN Scientific, Inc "Your Safer Source for Science Supplies" - Poster

Section II Laboratory Equipment PLC-Unit 1

Section III Scientific Method PLC-Unit 1

Scientific Method DEF: a systematic approach used in scientific study; an organized process used to do research and to verify the work of others a series of logical steps that scientists use to ask questions and solve problems PLC-Unit 1 13

Steps of the Scientific Method Ask a question Gather information Form a hypothesis Test the hypothesis Analyze the results Draw a conclusion Communicate results PLC-Unit 1 14

Ask a question How What When Who Why Where PLC-Unit 1 15

Gather Information research your problem (library, internet ) make observations DEF: a statement of fact based on sensory data Involves the five senses Sight Smell Hearing Taste Touch PLC-Unit 1 16

The flower has white petals Two types of observations Qualitative - DEF: an observation made without measurements describes what you observe “qualitative” = quality (description) The flower has white petals PLC-Unit 1 17

Quantitative - DEF: an observation made with measurement measures what you observe observations made with instruments (ruler, balance, graduated cylinder, thermometer,…) “quantitative” = quantity (numerical) The flower has 7 petals PLC-Unit 1 18

Qualitative vs Quantitative Qualitative: The road is long (describes) Quantitative: The road in 5 km long (numerical) Qualitative: The classroom is hot (describes) Quantitative: The classroom is 85oF (numerical) Qualitative: Mr. Richey has green eyes (describes) Quantitative: Mr. Richey has 2 eyes (numerical) PLC-Unit 1 19

Guided Practice Read the following examples and decide if they are qualitative or quantitative The classroom is cold qualitative The classroom is 60oF quantitative The volume is 40 mL quantitative The liquid is clear qualitative PLC-Unit 1 20

Assessment Read the following examples and decide if they are qualitative or quantitative The solution is green qualitative The cube is 9 mm long quantitative The temperature is 37.0oC quantitative It makes a loud pop sound qualitative PLC-Unit 1 21

Inference (Interpretation, Assumption) DEF: a judgment or opinion about what is observed Based on past experiences and prior knowledge PLC-Unit 1 22

Observation vs Inference Observation: The grass on the school’s front lawn is wet Inference: It rained The sprinkler was on There is dew on the grass from this morning The dog urinated on the grass All of these inferences can explain why the grass is wet. They are all based on prior experiences. We have all seen rain, sprinklers, morning dew, and dogs going to the bathroom PLC-Unit 1 23

? Guided Practice Observation: A student is sitting in the main office Possible Inferences: Why might a student be sitting there? ? PLC-Unit 1 24

Assessment Everyone is closing their book because… Students arrived to class sweaty because… All of the students are laughing because… PLC-Unit 1

Using the scientific method requires that one be a good observer. PLC-Unit 1

Form a Hypothesis DEF: a prediction that can be tested to explain observations can be written in the form of an “If..., then...” statement PLC-Unit 1 27

What effect does stirring have on solution rate? HYPOTHESIS A student is interested in designing several experiments to test the factors that effect how quickly an Alka-Seltzer® tablet dissolves in water (solution rate). QUESTION What effect does stirring have on solution rate? HYPOTHESIS If the water is stirred, then the tablet will dissolve faster. . LC-Unit 1 28

Guided Practice QUESTION HYPOTHESIS What effect does the water temperature have on solution rate? HYPOTHESIS If the water is heated, then the tablet will dissolve faster. LC-Unit 1 29

What effect does the amount of water have on plant growth? Assessment QUESTION What effect does the amount of water have on plant growth? HYPOTHESIS ? LC-Unit 1 30

Test a Hypothesis perform a controlled experiment DEF: a set of controlled observations that test the hypothesis consists of: Independent Variable Dependent Variable Control Group Constants LC-Unit 1 31

Independent Variable changed or manipulated in an experiment usually expressed after the word “if” in the hypothesis LC-Unit 1

Dependent Variable may change as a result of the independent variable usually expressed after the word “then” in the hypothesis LC-Unit 1

Identify the Variable independent variable If a student chooses to not study, then they will earn a poor grade. If you drink Gatorade before a soccer game, then you will score more goals. dependent variable independent variable dependent variable LC-Unit 1

Control Group same as the experimental group in every possible way, except for the factor being tested compare LC-Unit 1

Constants Factors kept the same and not allowed to change LC-Unit 1

Experimental Design Question: What effect does temperature have on popcorn? Hypothesis: If popcorn is stored in the freezer, then it will pop better Control: Popcorn stored at room temperature LC-Unit 1

Number of unpopped kernels Constants: Popcorn brand Microwave brand Independent Variable Storage Temperature Dependent Variable: Number of unpopped kernels LC-Unit 1

Analyze Results collect and analyze your data Data - DEF: any pieces of information acquired through experimentation PLC-Unit 1 39

create data tables / graphs Temperatures In NY City Day Temperature 1 43° F 2 53° F 3 50° F 4 57° F 5 59° F 6 67° F PLC-Unit 1 40

no experiment is a failure – just learned something new! Conclusion DEF: judgment based on the information obtained from your observations summary of your findings the results will either support or not support your hypothesis no experiment is a failure – just learned something new! PLC-Unit 1 41

“Tell the truth and nothing but the truth” PLC-Unit 1 42

Communicate Results lab report poster scientific journal Publish results lab report poster scientific journal PLC-Unit 1 43

Scientific Method Ask question Make observations Develop hypothesis Test hypothesis with an experiment Test hypothesis with further experiments Revise hypothesis Analyze data and draw conclusions Hypothesis IS supported Hypothesis is NOT supported Communicate Results PLC-Unit 1