Module 2, 2.2B Elements Lab

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Elements lab Report

Purpose:

To classify elements based on their properties.

Hypothesis:

None needed for this investigation.

Materials:

Five different elements that you can observe online or in person.

(You may check your periodic table for ideas).

Procedure:

Step 1.

Elements Symbol Colour State Metal, nonmetal or metalloid Conductivity Magnetic
Carbon C Black Solid Non-metal No No
Mercury Hg Silvery white Liquid at room temp. Metal Yes No
Neodymium Nd Silver grey Solid Metal Yes Yes
Silicon Si Reflective with bluish-tinged face Solid Metalloid No No
Helium He Colorless Gas Non-metal Yes No
Bromine Br Reddish Brown Liquid at room temp. Non-metal No No

Questions:

1.   Metals: Hg, Nd/Non-metal: He, Br, C/Metalloid: Si

2.   Hg, Nd, and He

3.   a) Solids at room temp – Exception: Mercury

b) Silver grey – Exception: Gold, Copper

c) Shiny – Metallic luster

4.  a) Found in all states (solid, liquid, gas)

b) Different colors

c) Without metallic luster

Conclusion:

In this experiment, I learnt that helium is actually a great conductor, and that is actually not a conductor at all (I thought it was a semiconductor). I also learnt the different colors, states, symbols, and magnetism of each element. In the future I would like to perform the same experiment but on a larger scale and with more or all the elements.

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Sheep Eye Disection

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Purpose: The purpose of my experiment is to compare the Cow eye with the human eye and see the similarities and differences.

Hypothesis: If I see the structures of the cow’s eye, then I would be able to observe how the human eye functions.

Materials:

  • Preserved sheep eye
  • Scissors
  • Prod
  • Dissection tray
  • Protective gloves
  • Paper towel
  • Plastic disposal bag
  • Wear protective gloves. Follow your teacher’s instructions to take them on and off.

Procedure:

  1. 1. Examine the eye before any action.
  2. 2. Use scissors to cut off the muscles and fat.
  3. 3. When you have taken most of the protective fat off the eye that covers the sclera and around the eye you should then have a round and ball like eye.
  4. 4. Then you poke a hole through the sclera so that you may be able to cut the eye in half with scissors.
  5. 5. Cut all the way around the eye. Try not to harm anything inside while cutting.
  6. 6. After you cut, separate the two parts of the eye apart.
  7. 7. Use the prod again and make a hole between the sclera and the cornea.
  8. 8. Use the scissors and cut around the cornea and remove it.
  9. 9. Take out the lenses and clear it from the jelly substance.

10. Put all the pieces of the eye in a disposal bag and clean up your work space and your hands.

Observations: I saw that the retina, where pictures are made into electrical signals and sent to the brain. I also saw the optic nerve which send the electrical signals to the brain. The lens was yellow and less flexible because it was old. This proves that as people age their lens decreases in flexibility.

Questions:

1. A: Sheep have an oval shape pupil, and the humans have a circular one.

B: Sheep have 4 muscles to move their eyes up, down, left, and right. But we have six       muscles so that we can roll our eyes.

C: The cow’s eye is much tougher than the human’s eye.

D: The cow’s eye is always one colour

2. 

3. Because the eye’s lens was old, it was hard, solid (not too much), and yellow. It was a little like an oval shape. I tried to see through it but it was too old.

Conclusions:

–       In the cow’s eye, under the cornea, you would find the iris which is an oval shape. But in the human’s eye, the iris is circular. This shows that our eye accepts more light because the more circular the eye is, the more it lets light enter.

–       I found a jelly-like substance between the cornea and the pupil. I remembered that it helps the cornea stay in great shape.

–       I think my results were accurate because I did figure out facts about the human eye while observing the cow eye.

–       I think my observations were important because when I saw the shapes, sizes and colors, I understood more about the eye and why it functions in the certain way.


Observing onion cells

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Purpose:

My goal is to learn more about staining and to compare between a stained slide and a non-stained slide.

Hypothesis:

If I use staining I would be able to see the cells and organisms better. It will be focused more on the cell and would not be too bright to see.

Materials:

  • Microscope
  • Prepared microscope slides
  • Cover slips
  • Lens paper
  • Tweezers
  • Medicine dropper
  • Water
  • Onion
  • Iodine solution
  • Paper towel

Procedure:

  1. 1. Gather all materials you need to do your experiment.
  2. 2. Use some tweezers to get the skin of the onion when you cut it in half.
  3. 3. Use a medicine dropper to drop a little water on the slide.
  4. 4. Place your onion skin on the drop of water.
  5. 5. Place a cover slip on top of the onion skin.
  6. 6. Now place the slide between the clips and the stage.
  7. 7. Observe and adjust with the course and fine adjustment knob, to get an accurate picture.
  8. 8. When you have pictured it, take the slide off the stage and wait for the next step.
  9. 9. Now use iodine solution to stain the slide. Place a paper towel on one side of the slide and iodine on the other.

10. When you have stained the cell, Place it again on the stage and adjust.

11. Compare between the non-stained and the stained onion skin.

12. Draw the onion cell as a diagram on a separate piece of paper.

13. Clean up all the materials you used and return them to your instructor.

Observations:

When I put the slide without the stain it was harder for me to figure out the difference between the cell and the background.

Questions:

  1. 1. The most difficult part was when I had to flatten the onion so that there would be no bubbles.
  2. 2. The nucleus was less clear without the stain because it was too bright. But when I put the stain it became clearer.
  3. 3. Because when we water a plant, the water goes to the vacuoles and holds it up. But when it tilts that means the plant is lacking water.

Conclusions:

I saw the nucleus only when it wasn’t stained. But when I got it stained I even saw the ribosome and some other organelles. My results were accurate and I learnt to try staining the slide whenever I can to see the cell and other things better on the microscope. I

How do you interpret your observations?

I think that when there is stain around the cell, then our eye can focus more on the brighter side of the slide. This staining make a difference which allows us to see the cell better.