Question

An element E has three isotopes:
$28\\\14 E$ (abundance 92.21%, atomic mass: 27.977 a.m.u.),
$29\\\14 E$ (abundance 4.70%, atomic mass: 28.976 a.m.u.), and
$30\\\14 E$ (abundance 3.09%, atomic mass: 29.974 a.m.u).
The atomic mass of E is _______ a.m.u.
(rounded off to three decimal places

Answer 1

The correct answer is: 28.082 to 28.089 (approx)