Question

a fictional element named nivad ium is found to have three naturally occurring isotopes with the natural abundances shown here: calculate the atomic mass of nivad ium. atomic mass = σ (fractional abundance × isotopic mass) 42.5 amu 24.8 amu 21.876 amu 23.123 amu 22.8 amu

Explanation:

Step1: Convert percentages to fractions

For \(45.0\%\), the fraction is \(0.45\). For \(10.0\%\), the fraction is \(0.1\).

Step2: Calculate each contribution

• For the isotope with mass \(22.17\) amu: \(0.45\times22.17 = 9.9765\)
• For the isotope with mass \(23.18\) amu: \(0.45\times23.18=10.431\)
• For the isotope with mass \(24.19\) amu: \(0.1\times24.19 = 2.419\)

Step3: Sum up the contributions

\(9.9765+10.431 + 2.419=22.8265\approx22.8\)

Answer:

\(22.8\) amu