A new element is discovered with 3 major isotopes. Its average mass is 118 u. The first isotope has a mass of 105 u and an abundance of 20%. The second has a mass of 125 u and an abundance of 27%. Find the mass of the third isotope a a whole number value.
I am so confused plz helpp!!
0.20 * 105 + 0.27 * 125 + 0.53x = 118
x = 119.34