The polio virus is 25 nanometers in diameter. how many would fit across the head of a pin 2 millimeters in diameter

80,000

Explanation:

First, the diameters of both must be in the same unit. Converting the pinhead diameter from millimeter to nanometer, we get:

nm

To get the number of polio viruses that fit at the head of the pin, divide the pin size by the amount of virus in nanometers:

This concludes that 80,000 polio viruses fit the pinhead.

the only liquid elements at standard temperature and pressure are bromine (br) and mercury (hg). although, elements caesium (cs), rubidium (rb), francium (fr) and gallium (ga) become liquid at or just above room temperature.

explanation: