(c) Polonium can undergo a phase transition (Phase I --> Phase II) to adopt a face-centred cubic
structure (where the metallic radius remains unchanged). Calculate the new unit cell dimension (in Å)
and the new density (in g. Cm-3) of the element (when in Phase II).
L
I
(d) Predict the form, i. E. , the first eight 20 values, of the X-ray powder diffraction pattern of this other
phase (Phase II) of polonium, where you should quote your 20 values to 2 decimal places (λ=154. 056
pm).
[6]
[6]
