2. (5 points) In nature, gallium consists of two isotopes, gallium-69 (mass = 68.926 amu and 60.1% natural abundance) and gallium- 71 (mass =70.925 amu and 39.9% natural abundance). Calculate the weighted average atomic mass of gallium. 3. (6 points) Menthol (molar mass 156g/mol ), a strong-smelling substance used in cough drops, is a compound of carbon, Hydrogen, and oxygen, when 0.1595g of menthol was subjected to combustion analysis, it produced 0.449 g of CO2 an 0.184g of H2O. What are menthol's empirical and molecular formulas