Practice problems (show all work): 1. how many significant figures are there in the following numbers? a. 0.008 = b. 9023 = c. 252.06 = 2. what is the volume of a salt crystal measuring 5.44 x 10-2m by 2.5 x10-3m by 7.9 x 10-3 m? 3. what is the quantity 750 milligrams expressed in grams? 4. what is the volume of 50.0 g of calcium if the density of calcium is .50 g/ml? 5. how did lavoisier transform the field of chemistry in the late 1700s?you.