a. How is the percent composition by mass determined? (.5 point) b. Determine the percent composition of each element in MgCl,. (1 point) i. Magnesium (Mg): (.5 point) ii. Chlorine

(CI): (.5 point) c. Calculate the empirical formula from the given percent compositions. 82% nitrogen (N), 18% hydrogen (H) (2 points)