You place a piece of paper on a balance and find that its mass is 0.63 g. You add a lump of NaOH to the paper and get a mass of 22.21 g. You remember that you forgot to tare the balance before taking this measurement. You tare the balance, add another lump of NaOH, and read 20.64 g. You add another lump of NaOH and read 38.98 g. How Much NaOH do you have on the balance, in grams, milligrams, micrograms and kilograms?