Which system of units is used by only a small number of countries in the world, including the U. S.?

"the periodic table is arranged in order of atomic number."

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

window cleaner is ammonia dissolved in water. this is an example of a