Objective 1.04 – Apply safety procedures in the laboratory and in field studies: Recognize and avoid potential hazards Safely manipulate materials and equipment needed for scientific investigations

Preventing Accidents Stop to think! Accidents in the science lab, as in the home or work place, can be prevented: Stop to think! Common sense will help, if exercised What will be the consequences of what I do next? If in doubt, ask the teacher.

Eye Protection Correct! Safety goggles should be worn when using chemicals or when pointed objects or tools are being used. Safety goggles can be used by more than one person if sterilized between uses. Goggle sanitizers are used for this purpose. Not Acceptable!!

Proper Attire Avoid floppy garments; avoid things that dangle These get tangled up in equipment or glassware and cause accidents Avoid long, loose hair styles for the same reason. When Bunsen burners are in use, long hair sometimes catches on fire It is not safe to wear open footwear, so avoid sandals and flip flops on lab days.

Safety With Heat Sources Never touch a hot surface like a hot plate or boiling water in your classroom. If something is heating, be mindful of cords on the lab bench.

Using Dangerous Materials Use only alcohol thermometers – these are red/green and not metallic. Never taste or put anything in your mouth in the science lab. Notify a teacher immediately in the case of a liquid spill.

Broken Glass Tell the teacher! Sweep it up right away - Don’t track in it all period Place the broken glass in a SHARP’S CONTAINER – never in the regular trash can.

How to Properly Smell a Chemical Never place your nose directly above an unknown substance. Gently wave your hand above the open container up toward your nose to waft the odor toward you.

Never Eat or Drink in the Science Lab! A good practice is to assume everything in the lab is toxic. DO NOT drink from lab equipment. NOT EVEN distilled water. You do not know what another person might have added to the "distilled water" jug.

Horseplay In a laboratory setting, horseplay, even if good-natured, is absolutely unacceptable. No pushing! No shoving!

Science Lab Safety Features Fire Extinguisher

Fire Blanket

Eye Wash Station

Fume Hood

Lab Safety Symbols Flammable materials

Lab Safety Symbols Electricity in Use

Lab Safety Symbols Fumes

Lab Safety Symbols Corrosive materials

Lab Safety Symbols Sharp materials

Lab Safety Symbols Poisonous materials

Lab Safety Symbols Wear Goggles

Lab Safety Symbols Live Animals in Use

Warmup List the steps of the scientific method.

Measuring & Graphing

A Scientist’s Equipment Beaker Test Tube

A Scientist’s Equipment Funnel Pipet

A Scientist’s Equipment Erlenmeyer Flask Graduated Cylinder

A Scientist’s Equipment Triple Beam Balance Thermometer

Measuring Mass 133.3 g

Measuring Mass 150.5 g 120.5 g

Measuring Distance Use the small side of the ruler to measure cm (eventhough it says mm)! 4.7 cm

Measuring Volume 14 mL

Measuring Volume

Graphs There are 3 kinds of scientific graphs: Bar Graphs Line Graphs Used for comparison Line Graphs Used to show continuing data Pie Charts (Circle Graphs) Used to show parts of a whole

Bar Graphs What is the average number of seeds planted? What is the range of the data? Three-fourths of the seeds planted on Thursday were watermelon seeds. How many of the seeds planted on Thursday were not watermelon seeds? Number of Seeds Planted

Monthly Rainfall in Muddytown Line Graphs On which month(s) was there at least 12 inches of rain? Between which two months was there the greatest decrease in rain? What is the difference in inches of rain between the month with the most rainfall and the month with the least rainfall? Monthly Rainfall in Muddytown

Pie Charts List the seasons in order from the season with the fewest votes to the season with the most votes. What is the most popular season? A     Fall  37% B Summer  21% C Spring  23% D Winter  19%

Warmup If you don’t know what to do before conducting an experiment, what should you do? Your behavior in class and during lab activities dictates if you can…

The Scientific Method

Observations Scientific thinking usually begins with observation, the process of gathering information about events or processes in a careful, orderly way. Observation involves using the senses: sight, hearing, touch, taste, smell.

Making Observations Take a minute to write down as many observations about the picture as you can.

Data The information gathered from observations is called data. There are two kinds of data: Quantitative data ~ numbers from counting or measuring Qualitative ~ descriptions Which kind of data did you collect about the picture?

Inferences Data can be used to make inferences. An inference is a logical explanation based on prior knowledge or experience. Scientists try to explain events in the natural world by interpreting evidence logically and analytically.

Making Inferences Infer what is happening in the picture.

Hypothesis After initial observations, the researchers will propose one or more hypotheses. A hypothesis is a proposed scientific explanation for a set of observations. Scientists generate hypotheses using prior knowledge and inferences from observations. Scientific hypotheses must be able to be tested.

Setting Up a Controlled Experiment Testing a hypothesis involves designing an experiment. The factors in an experiment that can change are called variables. Examples of variables include: temperature, time & light

Controlled Experiments Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled. This type of experiment is called a controlled experiment.

Variables The variable that is deliberately changed is called the independent variable (manipulated variable). The variable that is observed and that changes in response to the manipulated variable is called the dependent variable (responding variable).

Recording and Analyzing Data Scientists usually keep written records of their observations or data. Sometimes, drawings record certain kinds of observations more accurately. Numerical data is usually recorded into a table, and analyzed using graphs.

Drawing a Conclusion Scientists use the data from an experiment to evaluate a hypothesis and draw a valid conclusion. They use evidence to determine whether the hypothesis was supported or rejected.

The Scientific Method Ask a Question Make Observations Form a Hypothesis Controlled Experiment Record and Analyze Data Draw a Conclusion

Reliability A key assumption in science is that experimental results can be replicated because nature behaves in a consistent manner. When one particular variable is manipulated in a given set of variables, the result should typically be the same.

Squidward’s Symphony Squidward loves playing his clarinet & believes it attracts more jellyfish than any other instrument he has played. In order to test his hypothesis, Squidward played a song on his clarinet for a total of 5 minutes and counted the # of jellyfish he saw in his front yard. He played the song a total of 3 times on his clarinet and repeated the experiment using a flute and a guitar. He also recorded the number of jellyfish he observed when he was not playing an instrument. The results are shown in the chart. Trial No Music Clarinet Flute Guitar 1 5 15 12 2 3 10 8 18 9 7 What is the independent variable? What is the dependent variable? What should Squidward’s conclusion be? Are the results reliable?

Inquiry Lab Observations: Questions: Write down as many observations as you can. Keep any inferences in a separate column Questions: Write down as many questions as you can.

Inquiry Lab Choose one of your questions… What is your hypothesis How would you test it? What other materials would you need? What is your procedure?