To divide one power of ten by another, simply subtract the two exponents (see Multiplication/Division). Next, convert the two numbers from scientific notation to real numbers. Now add the two numbers normally. Finally convert to scientific notation if the coefficient is less than 1 or greater than 10.
Precipitation occurs when cloud droplets combine and grow large enough to fall to the earth the rate of evaporation as a drop falls to the earth also can affect its size. from: sadia aisa.
Precipitation in chemistry refers to the creation of a solid within a solution or within another solid during the process of diffusion. During this process, the solid formed is known as the precipitate. What causes the solid to form is known as the precipitant, and the supernate or supernatant is the area above the precipitate.