Moseley established the concept of atomic number by studying X-rays emitted by the elements. The X-rays emitted by some of the elements have the following wavelengths:
Element Wavelength (A)
Ne .............................. 14.610
Ca ................................ 3.358
Zn ................................ 1.435
Zr ................................. 0.786
Sn ................................. 0.491
(a) Calculate the frequency, v, of the X-rays emitted by each of the elements, in Hz.
(b) Using the appropriate graphing program on your computer, plot the square root of versus the atomic number of the element. What do you observe about the plot?
(c) Explain how the plot in part (b) allowed Moseley to predict the existence of undiscovered elements.
(d) Use the result from part (b) to predict the X-ray wavelength emitted by iron.
(e) A particular element emits X-rays with a wavelength of 0.980 Å. What element do you think it is?