Measurements and Calculations

[Mick Preston]

Scientifically oriented question: What is the estimated size of an oil molecule?

 

Evidence: After adding powder to the water I placed one drop of oil in. I measured it and found that it was about .5mm in diameter, and if you talk half of .5 you will get the radius, which is .25mm. By knowing that information you can find the volume of the oil drop. The formula is 4/3*pi(r)^3. We plugged in .25 for the radius and got .065cm^3 as the volume. Next we had to find the spread of the oil drop, and 95mm was the diameter, and 47.5mm was the radius. Our group also had to find the area of the oil drop and we got .196mm^2 and the thickness was .331mm.

 

Explanation: By getting measurements like the volume and the spread, we were able to use those to get the thickness. The thickness was the height of the oil drop. In other words the size of the molecule was .331mm.

 

Connection: Finding out the size of the oil drop is related to real life situations. The lab helps us understand nanotechnology which is the engineering of functional systems at the molecular scale. Scientists can use this to distiguish between different elements by knowing the size. Doctors use this when they are giving medicine to someone. They need to know the size of it so they don't give them too much or too little.

 

Communictation: If I was talking to classmates I would be able to help them because I could show them how to calculate the measurements. By understanding nanotechnology I would also show them the correct way to measure the sizes. Once you get one measurment, like the diameter, you can figure out different things like the volume. If you understand all of this you can eventually find out the thickness of the oil drop.

 

Reflection: Other students have similar calculations and measurements. Although some of the groups have different answers, so I need to figure out where one of us went wrong. It could be from the measurements they made which could of been different, or it could be something that one of us plug in wrong into the equation.