the atomic masses of nitrogen-14, titanium-48, and xenon-129 are 13.999234 amuamu , 47.935878 amuamu , and 128.904779 amuamu , respectively. part a calculate the nuclear masses of all three isotopes. express your answers in atomic mass units to six decimal places separated by commas. m(14n)m(14n) , m(48ti)m(48ti) , m(129xe)m(129xe)