unsur x mempunyai isotop x1=massanya 35 dan x2=massanya 37,jika massa atom relatif (Ar x) =35,5 tentukan kalimpahan isotop x1 dan x2..

Isotop, isoton, isobar

Ar X = x% . 35 + (100 – x)% . 37
35,5 = x/100 . 35 + (100 – x)/100 . 37
3550 = 35x + 3700 – 37x
35x - 37x = 3550 - 3700
-2x = -150
x = 75

Kelimpahan X = 100 - 75 = 25%