Question

In a sample of 1000 atoms of an unknown element, it is found that 14 are isotopes of mass 203.973 amu, 241 are isotopes of mass 205.9745, 221

are isotopes of mass 206.9759, and the remaining 524 are isotopes of mass 207.9766 amu. Calculate the average atomic mass of the unknown substance.

Answer 1

To calculate the average atomic mass of an element, you need to multiply the mass of each isotope by its relative abundance and then add the products together.

Step-by-step explanation:

To calculate the average atomic mass of an element, you need to multiply the mass of each isotope by its relative abundance (expressed as a decimal), and then add the products together. In this case, the unknown element has four isotopes with masses of 203.973 amu, 205.9745 amu, 206.9759 amu, and 207.9766 amu. The respective abundances are 0.014, 0.241, 0.221, and 0.524. To calculate the average atomic mass, you would multiply each mass by its respective abundance, and then sum the values. The calculation would look like this: (203.973 amu * 0.014) + (205.9745 amu * 0.241) + (206.9759 amu * 0.221) + (207.9766 amu * 0.524) = x amu.