This question is about two transition metals, hafnium (Hf) and zirconium (Zr).

a. Hafnium forms a peroxide whose formula can be written as HfO₃.2H₂O. Use the A_r values below to calculate the relative molecular mass of hafnium peroxide.
(A_r values: Hf = 178.5, H = 1.0, O = 16.0)

b. A particular isotope of hafnium has 72 protons and a nucleon number of 180. Write the isotopic symbol for this isotope, showing this information.

c. The mass spectrum of zirconium is shown below.

i. Use the information from this mass spectrum to calculate the relative atomic mass of zirconium. Give your answer to 3 significant figures.
ii. High-resolution mass spectra show accurate relative isotopic masses. What do you understand by the term relative isotopic mass?

Transcribed Image Text:

100 80 - 60 40 20 90 95 Mass/charge (m/e) ratio Abundance/ % 51.5% 11.2%