The half-life of radon-222 is 3.8 days. if a sample currently contains 3.1 grams of radon-222, how much radon-222 did this sample have 15.2 days ago? a 12.4 grams b 47.1 grams c 49.6 grams d 57.8 grams

The following reaction shows the products when sulfuric acid and aluminum hydroxide react. al(oh)3 + h2so4 → al2(so4)3 + h2o the table shows the calculated amounts of reactants and products when the reaction was conducted in a laboratory. sulfuric acid aluminum hydroxide initial amount of reactant 40 g 15 g theoretical yield of water from reactant 14.69 g 10.38 g what is the approximate amount of the leftover reactant? 11.73 g of sulfuric acid 10.33 g of sulfuric acid 11.12 g of aluminum hydroxide 13.67 g of aluminum hydroxide