Answer to Question #229269 in General Chemistry for Cheswell

Question

The isotopic makeup of an element is determined by Mass Spectrometry, a method for

measuring the atomic masses and abundances of atomic-scale particles very precisely.

Silicon-28 was analysed in a Mass Spectrometer and a ratio of 2.331411 was

obtained. Determine the atomic mass of silicon-28.

Answer 1

Silicon-28: Mass = 27.9769 amu f.a. = 92.18% ÷ 100 = 0.9218.

silicon-28 atom (CHEBI:37975) The stable isotope of silicon with relative atomic mass 27.9769265.

0.9218 = 27.9769

2.331411 = ?

= 70.76