Chlorine has two naturally occurring isotopes, 35Cl with a mass of 34.969 and 37Cl with a mass of 36.966. The relative atomic mass of Cl is 35.5. Calculate the percentage abundance of each isotope.
A sample of cerium, Ce, was analysed in a mass spectrometer. The relative abundances of three of the four main isotopes that were identified are shown in the table below.
A sample of cerium, Ce, has four isotopes that have a known relative abundance. This sample has an Arof 140.12.
Isotope
136Ce
138Ce
140Ce
mCe
Abundance (%)
0.19
0.25
88.45
To be calculated
Use the data from the table to calculate m, the mass number and the percentage abundance of isotope mCe.
A sample of element Z was extracted from a meteorite. The table shows the relative abundance of each isotope in a mass spectrum of this sample of Z. Calculate the relative atomic mass of Z and suggest an identity of Z. Give your answer to 1 d.p.
Calculate the percentage abundance of 63Cu with a mass of 62.9296 and 65Cu with a mass of 64.9278, when the average mass of the Cu isotope is 63.546. Give your answer to an appropriate number of significant figures.
2-chloro-2-methylbutane contains some molecules with a molar mass of approximately 106 g mol-1 and some with a molar mass of approximately 108 g mol-1.
Outline why there are molecules with different molar masses.