Lab Safety, Scientific Method, and Microscopes

Steps of the scientific method Observations/Testable Question/Problem Hypothesis Experiment Data Conclusion

What is the optimum amount of water to give a plant? Example Experiment: What is the optimum amount of water to give a plant?

1. Observation/Testable Question/Problem: Determine what you are trying to figure out by writing a testable question. Plant Example Does changing the amount of water a plant receives affect its growth?

2. hypothesis Plant Example Make an educated guess about what you think the outcome of your experiment might be. If____________, then_____________________. Plant Example If I water a plant with 1 cup of water per week then it will grow faster than a plant given ½ a cup of water per week.

3. experiment Plant Example Design a plan to test if your hypothesis is correct or not. Your experiment should include 3 or more trials or test subjects. (Repetition helps yield more reliable results!) Plant Example Grow 3 of the same plant for 10 weeks. Each plant is given different amounts of water per week. They should be placed in the same environment. Their height will be measured in cm. once a week. There will be three duplicates of each plant.

Variables Plant Example Control Variable: The factors that stay the same for each group in the controlled experiment. Independent Variable: the one factor that is changed or different from one test subject to another in a controlled experiment. Dependent Variable: the factor that is measured in a controlled experiment Type of plant & Environmental conditions The amount of Water given to each plant Plant Growth

4. data Plant Example Collect your measurements and analyze them. Water Amount Week1 Week 2 Week 3 Week4 Week 5 Week 6 Week 7 Week 8 Week 9 Final Height 1 cup 1cm 1.5cm 1.7cm 2cm 2.4cm 3cm. 3.5cm 4cm 5cm 10cm ½ cup 1.1cm 1.8cm 2.5cm 3cm 7cm No Water 1.6cm 1.9cm

5. Claim and conclusion Plant Example Make a claim about the outcome of your experiment and support that claim with evidence and data you have collected. Plant Example Conclusion Claim: Plants grown taller when watered with 1 cup of water than when watered with ½ cup of water. Evidence: The data showed that the plant given 1 cup of water per week has a final height of 10 cm while the plants given half a cup of water per week had a final height of 7cm.

Design your own Experiment In this activity, you will work through the steps of the Scientific Method to design an experiment that will test one of the following themes: distance, speed, size, or height. You will then conduct your experiment, analyze your data, and make conclusions. You may use any of the materials available in the classroom. Be sure to answer each question in complete sentences! You can use any of the supplies on the counter or anything else in the room (just ask first) You will come up with a testable question, design the experiment, collect data, then form a claim and evidence.

Microscopes

Microscope Worksheet Use the table to label and color code the microscope diagram. Make sure to fill in the color box on the left of the table! You have 8 minutes!

Types of Microscopes Dissecting Microscope -  can all be used for science dissection projects, viewing printed circuit boards, or quality inspection tasks. Each dissection microscope (not including the handheld microscope) has both a top light and a bottom light, each of which can be used independently of the other. Most often, the top light is used while dissecting Light Microscope -  the models found in most schools, use compound lenses to magnify objects. The lenses bend or refract light to make the object beneath them appear closer. Common magnifications: 40x, 100x, 400x

Magnification Your microscope has 3 magnifications: Scanning, Low and High. Each objective will have written the magnification. In addition to this, the ocular lens (eyepiece) has a magnification. The total magnification is the ocular x objective

Ocular lens (Eyepiece) Body Tube Nosepiece Arm Objectives Stage Stage Clips Coarse Adjustment Diaphragm Fine Adjustment Light Always carry a microscope with one hand holding the arm and one hand under the base. Base

You do not need to use the stage clips when viewing wet-mount slides! How to make a wet-mount slide … 1 – Get a clean slide and coverslip from your teacher. 2 – Place ONE drop of water in the middle of the slide. Don’t use too much or the water will run off the edge and make a mess! 3 – Place the edge of the cover slip on one side of the water drop. 4 - Slowly lower the cover slip on top of the drop. Cover Slip Lower slowly You do not need to use the stage clips when viewing wet-mount slides! 5 – Place the slide on the stage and view it first with the red-banded objective. Once you see the image, you can rotate the nosepiece to view the slide with the different objectives.

Microscope Golden Rules Rule 1: Always carry microscopes with two hands, by the arm and the base. Rule 2: Always start off on the lowest power objective lens, get objects into focus, and then move up. Never use the coarse adjustment knob on the higher powers.

Microscope Stations Lab There are 7 microscope lab stations set up around the room: Station 1: Online Microscopes (using the chromebooks) Station 2: Select-A- Slide (Observing premade slides) Station 3: Dirty Water (wet, mount practice while observing dirty water) Station 4: Your Fingerprint (You will figure out your own fingerprint pattern) Station 5: Scope Basics (You will practice microscope vocabulary and labeling) Station 6: Newspaper letters (practice viewing small objects and learning how the lens project objects using small newspaper print) Station 7: Mystery Objects (view 3 mystery objects under a microscope and make observations)

Microscope Stations Lab You must read each station card and follow directions EXACTLY Be sure to record and answer all question on your lab sheet IN COMPLETE SENTENCES. You will have 10 minutes at each station, so make sure everyone gets a chance to observe and complete the tasks. Remember Golden Rule #2 Always start off on the lowest power objective lens, get objects into focus, and then move up. Never use the coarse adjustment knob on the higher powers.