In: Chemistry
Gallium has two isotopes, 69Ga and 71Ga; 60.11 % of gallium is 69Ga and 39.89 % is 71Ga. The atomic mass of 69Ga is 68.926 amu and the atomic mass of 71Ga is 70.925 amu . What is the atomic weight of gallium?
Ans. Average atomic weight of Ga = (% 69Ga x its atomic mass) + (% 71Ga x its atomic mass)
= (60.11 % x 68.926 amu) + (39.89 % x 70.925)
= 41.4314186 amu + 28.2919825 amu
= 69.7234 amu