Question

Calculate the atomic mass of the unknown element X described below.
Please help

Answer 1

Answer:

286

Explanation:

Add atomic mass of all the Isotopes,

                                          Outcome = 825

divide it by number of isotopes which is 4 because there are 4 isotopes

                       Atomic mass of x = $\frac{825}{4}$

                       Atomic mass of x is 286