Ablue whale has a length of 28,578 millimeters. what is the length of a blue whale in kilometers? show your work below by writing the conversion factors you use to solve this problem

Milli word means 1/1000 times while kilo word means 1000 times. That means a milli meter will be equal to 1/1000 meter while 1 kilometer is equal to 1000 meters. The conversion factor would be: 1 millimeter * (1 meter/1000millimeter) / (1000 meters/1 kilometer)= 1 * 10^-6 kilometer. The conversion factor is 1 * 10^-6 kilometer/mm

Since 1 mm equal to 1 * 10^-6 kilometer, the whale length would be:28,578 millimeters * (1 * 10^-6 kilometer/mm)= 0.028578 km= 2.85 * 10^-2 km

Leeuwenhoek heated the middle of a small soda glass rod , over a flame. On pulling apart the two ends, the glass rod elongated into thin whiskers . 
Heating the end of this whisker resulted in a tiny high quality glass sphere. These glass spheres then became the lens of his microscope, with the smallest sphere providing the greatest magnification.

Leeuwenhoek's designs were very basic. The body of the microscope was a single lens mounted in a tiny hole on a brass plate. The specimen was then mounted on a sharp point that sticks up in front of the lens. It's position and focus could be adjusted by turning the two screws.

The entire instrument was about 3 to 4 inches long and had to be held up close to the eye, requiring good lighting and great patience to use.