Issued as a cumulative or non-cumulative L/C, the former allows for unused credit amounts to rollover into subsequent periods while the latter maintains a fixed amount of credit available each period.
average atomic mass of magnesium is 24.3 g/mole so 24.3 X 1.56 X1021 / 6.02 X1023 = .063 grams.
Magnesium is the 12th element in the periodic table, having an atomic number 12 and atomic symbol Mg. It was isolated in 1808 by Sir Humphry Davy. It is one of the most widely found elements on the Earth. It is silvery white in color, slightly inflammable, and burns with a white flame.