An empty test tube weighs 13.344 g empty and 22.708 g when completely filled with water at room temperature (25 degree C). When a sample of zinc beads was added first to the empty test tube, then filled with water, the total mass was 31.312 g at room temperature. What was the mass of the zinc sample in grams? (At 25 degree C, the density of water = 0.997044 g/mL and the density of zinc = 7.140 g.cm^3.)