How much hydrogen's will remain after A years if the original sample had a mass of G?

To determine how much hydrogen will remain after A years from an original sample mass of G, you would need to know the half-life of hydrogen, which in this context typically refers to the isotopes of hydrogen used in nuclear reactions, such as tritium. The remaining mass can be calculated using the formula ( R = G \times (0.5)^{(A/T)} ), where ( T ) is the half-life of the isotope in years. Without specific values for A and T, it's impossible to provide a numerical answer.