The diameter of the average cell in the human body is 1 x 10-5 meters. the diameter of a grain of sand is about 2 x 10-4 meters. the diameter of a human hair is about 0.000025 meters. the smallest known bacteria are from the genus mycoplasma and can measure as small as 300 nanometers in diameter. given that 1 meter = 1 x 109 nanometers, what is the diameter of the smallest bacteria, in meters? give your answer in scientific notation and show your work.