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.
Depending on the particular chemistry the precipitate may or may not settle. Precipitation occurs when a <i>medium</i> in which a substance had previously been absorbed/dissolved, suffers a change so that the substance can no longer be supported in suspension.