If the interplanar distance in the crystal is 287pm , and the angle of maximum reflection is found to be 7.28?, what is the wavelength of the x-ray beam? (Assume n=1.)
72.7 pm
n(wv)2dsin(angle)
wv=2dsin(angle)/n
Gallium crystallizes in a primitive cubic unit cell. The length of an edge of this cube is 362 pm. What is the radius of a gallium atom?
radius=181 pm
primitive= 1 atom per cell
The face-centered gold crystal has an edge length of 407 pm. Based on the unit cell, calculate the density of gold.
d=19.4g/cm^3
4 atoms
mass=(1.308x10^-21)
d^3
v=6.74x10^-23
Chromium crystallizes with a body-centered cubic unit cell. The radius of a chromium atom is 125 pm. Calculate the density of solid crystalline chromium in g/cm3
d=7.18 g/cm^3
What is the length of the line (labeled c) that runs from one corner of the cube diagonally through the center of the cube to the other corner in terms of r(the atomic radius)?
c=4r
Use the Pythagorean theorem to derive an expression for the length of the line (labeled b) that runs diagonally across one of the faces of the cube in terms the edge length (l).
b=sqrt(l^2+l^2)
Use the answer to part (a) and (b) along with the Pythagorean theorem to derive the expression for the edge length (l) in terms of r.
l=4r/sqrt3
Molybdenum crystallizes with a body-centered unit cell. The radius of a molybdenum atom is 136pm .
Edge length?
l=314 pm
Molybdenum crystallizes with a body-centered unit cell. The radius of a molybdenum atom is 136pm .
Density?
10.3 g/cm^3
The density of an unknown metal is 12.3g/cm3 and its atomic radius is 0.134nm . It has a face-centered cubic lattice. Atomic Weight?
101 g/mol
The unit cell in a crystal of diamond belongs to a crystal system different from any we have discussed. The volume of a unit cell of diamond is 0.0454 nm3 and the density of diamond is 3.52 g/cm3.
8 atoms
An X-ray beam of ? = 73.66pm is incident on the surface of an atomic crystal. The maximum reflection occurs at an angle of 37.6? .
Calculate the separation between layers of atoms in the crystal
60.4 pm
What is the coordination number (the number of atoms each atom touches) in a face-centered cubic unit cell?
12
How many atoms are in the body-centered cubic unit cell?
2
Aluminum crystallizes in a face-centered cubic unit cell. The radius of a aluminum atom is 143 pm.
Determine the density of aluminum in g/cm3.
2.71 g/cm^3
Which type of solid is table salt (NaCl)?
ionic
high melting point