WorksheetsAverage Atomic Mass Spectrum
Total questions: 6
Worksheet time: 2hrs 30mins
Determine the percent abundance for Fe-57, given the following above. The average atomic mass for Fe is 55.845 u.
2.13
0.27
2.70
0.21
Naturally occurring strontium consists of four isotopes, Sr-84, Sr-86, Sr-87 and Sr-88, whose isotopic masses are 83.9134, 85.9094, 86.9089 and 87.9056 amu respectively.
The most abundant isotope is Sr-88 which accounts for 82.58% of naturally occurring strontium and the least abundant isotope is Sr-84 which accounts for 0.56% of naturally occurring strontium.
Given that the observed atomic mass of strontium is 87.62 amu, calculate the percentages of Sr-87 in nature.
7.34
9.52
92.66
9.27
Oxygen is composed of three isotopes: One has a mass of 16.999 amu. This isotope makes up 0.037% of oxygen. Of the other two, one has a mass of 15.995 amu, and the other has a mass of 17.999 amu.
Calculate the abundance of the other two isotopes, using the average atomic mass of 15.9994 amu.
99.76 & 0.203
89.67 & 1.28
99.76 & 0.037
0.203 & 3.70
The atomic weight of lead is 207.19 amu. Assuming that it's made up of entirely the isotopes of Pb-206 (205.98 amu); Pb-207 (206.98 amu); and Pb-208 (207.98 amu) and that the percentages of the two lightest isotopes are equal, calculate the relative percentages of these isotopes in the natural element.
Pb-206: 26.3%
Pb-207: 26.3%
Pb-208: 47.4%
Pb-206: 36.3%
Pb-207: 36.3%
Pb-208: 27.4%
Pb-206: 16.3%
Pb-207: 16.3%
Pb-208: 67.4%
Pb-206: 10.3%
Pb-207: 10.3%
Pb-208: 79.4%
A sample of boron with a relative atomic mass of 10.8 gives a mass spectrum with two peaks, one at m/z = 10, and one at m/z = 11.
Calculate the ratio of the heights of two peaks.
4:1
2:3
2:2
4:2
Antimony, Sb, has two stable isotopes. Given that 43.8% of natural antimony is Sb-123 with the experimentally determined mass of 122.904 amu.
What is the other stable isotope?
Sb-121
Sb-122
Sb-124
Sb-125
