Question

The element Po or Polon is the largest element in class 16 and the only element that has a sc (simple cubic) crystal structure. An x-ray analysis was performed on the crystal where the angle of the beam (θ) m. the surface of the crystal was 15.45 ° and the wavelength of the beam (λ) was 1.785 x 10-10 m?

a) What is the distance between the nuclei of the atoms in the crystal?

b) What is the diameter of the Po atom?

c) What is the density of Po?

Answer 1

Q Given element Polon has simple cubic structure pad. Alle Angle of the beam to the surface of crystal 0=15.45° Wavelength Lt) = 1.785 x 101m. Distance between the nuclei of the atome of crystal will become the distance betwee) the distance between two Lattice points. ( simple cubic structure) By Bragg's law nis ed sine - Here na) . de nt . 1)(1.785x6519 2lino 2x Sink 15.45) 1.785X10 to 053279 = 3.35028 x 10 to d = 335 pm] = G b distance is Since it equal to - is simple cubic, the diameter of Polon atom Diameter = 335pm .

© Volume Density a mass Density of Polonium can be found by determining the density of its unit cell. 1. Since a po unit cell contains one-eighth of a po atom at each of its eight corners, a unit cell contains One Po atom. . Mass of Po cenit & Ind. Po 208.998g M = 1 Po unit cell x ! Po atom. 1 Po Ut cell 6.022 X 123 Yamal Po atoms. = 3.47 x1622g volume of a Po unit cell: Vad} = (335x10.com) = 3.79 21073 cm? Density = m/v 3.471x1522 - 3.79% 1623 cm3 Density = 9.16 glems.