Element Yourneighbor (Yn) has an atomic mass of 126 amu and has six known isotopes. Isotope 1 has a mass
of 120 amu and a relative abundance of 8%. Isotope 2 has a mass of 117 amu and a relative abundance of
12 %. Isotope 3 has a mass of 130 amu and a relative abundance of 5%. Isotope 4 has a mass of 125 amu
and a relative abundance of 30%. If isotopes 5 and 6 have the same relative abundance and isotope 6 has a
mass of 131.4 amu, what is the mass of isotope 5 and the relative abundances of isotopes 5 and 6 ?