There are only two isotopes of gallium: ^69ga (68.926 amu) and ^71ga(70.025 amu). the average atomic mass of gallium is 69.723 amu. what is the percent of abundance of gallium-69? show all calculations involved.

Equal numbers of moles of he(g), ar(g), and ne(g) are placed in a glass vessel at room temperature. if the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the gases remaining in the vessel after some of the gas mixture has effused?