Archive for Science 6
A group of kids is on a rowboat in the lake when they find a stone on the boat with them and they throw the rock overboard and the rock sinks to the bottom.
I think that the lake would rise very slightly because when the rock is on board the boat it’s floating. When it’s dropped into the lake the full weight of the rock is dropped into the lake and it makes the water level rise very slightly.
In science class we looked at onion and cheek cells under a microscope. We chose a partner. My partner was Sean.
We started by peeling one layer of the onions skin. We put the skin of the onion onto a glass slide. Then we stained the onion with one brown iodine drop to make the cells visible. We put a cover slip on top of that and then we slid the slide under the microscope. We put the range at the tallest and turned the lens to 4. Once we found the cells we went to 10 then 40. When we used 100 it was too strong so we couldn’t see anything.
There were safety issues which were if we got iodine on our clothes it would be permanent and if we got in on our skin it would be there for a week. If you got onion in your eyes it would make you cry. If the cover slip broke it would get into your skin and it would hurt. You can spread diseases by using the same chopsticks. If you get H2O on the microscope it damages the microscope. If you carry the microscope incorrectly the microscope can brake or you drop the microscope. If the lenses get dirty you can get mistaken with the cells and the dust cells.
The onion cells were connected and they weren’t moving. The cells had little dots inside it.
We used a chopstick to scrape off cheek cells to put on a slide (everyone used different chopsticks). We used methyl blue to stain the cheek cells. I tried over and over but I never found my cheek cells.
It was difficult to find my cheek cells but it was easy to find the onion cells.
There is a nob on the side that make the slide farther and closer. We use that to focus the lens.
In science we mixed 50ml of ethanol with 50ml of water. The ethanol smelled like soap.
50ml of water mixed with 50ml of ethanol will make 100ml of water-ethanol mixture because 50ml+50ml=100ml.
When you mix ethanol with water the liquid started bubbling. Instead of there being 100ml of liquid there was 95ml. The beaker was warm.
Why that happened:
The reason why the volume decreased because the ethanol molecules are smaller than the water molecules. So, the ethanol molecules get crammed in between the water molecules. That’s why there was a decrease in volume. I found this out at this link. Before I read this article I thought the liquid evaporated because I saw the bubbles.
Today we put sand in a container so the sand was more dense than the water so the container sank. But the sand was less dense than the salt water the container floated. If something less dense than fluid the something floats. Water is 1gram per cubic centimeter dense so if something is more dense it sinks. If something is less dense than water it floats.