The Atomic Mass Of Lithium Assignment
5-13. Challenge problem. Richards and Willard determined the atomic mass of lithium and collected the following data.
Experiment (a) Find the mean atomic mass determined by those workers.
(b) Find the median atomic mass.
(c) Assuming that the currently accepted value for the atomic mass of lithium is the true value, calculate the absolute error and the percent relative error of the mean value determined by Richard and Willard.
(d) Find in the chemical literature at least three values for the atomic mass of lithium determined since 1910 and arrange them chronologically in a table or spreadsheet along with the values since 1817 given in the table on page 10 of the paper by Richards and Willard. Construct a graph of atomic mass versus the year to illustrate how the atomic mass of lithium has changed over the past two centuries. Suggest possible reason(s) why the value changes abruptly in about 1830.
(e) The incredibly detailed experiments described by Richards and Willard suggest that it is unlikely that major changes in the atomic mass of lithium will occur. Discuss this assertion in light of your calculation in part c.
(f) What factors have led to changes in atomic mass since 1910?
(g) How would you determine the accuracy of an atomic mass? Get Science homework help today