Question

An element, X has the following isotopic composition :
²⁰⁰X : 90% ¹⁹⁹X : 8.0 % ²⁰²X : 2.0 %
The weighted average atomic mass of the
naturally occuring element X is closest to
(a) 201 amu (b) 202 amu
(c) 199 amu (d) 200 amu

Answer 1

Answer:

d. 200 amu

Explanation:

Av.atomic mass=(90×200+8×199+2×202)/100

=199.96 amu (nearly equal to 200 amu)