Slip in NaCl-structure ionic crystals (such as NaCl, TiC, TaC, etc.) occurs most commonly on {110} planes and in (10) directions. Draw the (110) plane and the 10 direction in a cubic cell of this crystal (there is no need to include the atoms) upon application of a load of 1,000 N and determine the resolved shear stress The direction of load application is along the [211] direction of the crystal. The cross-sectional area of the crystal is circular and of 10-cm diameter.

A diffracrometer using X-rays with a wavelength of 0.2287 nm produced first-order diffraction peak for a crystal angle =16.21. Determine the spacing between the diffracting planes in this crystal.

Gold crystallizes in a face-centered cubic unit cell. The second-order reflection ( n=2) of X-rays for the planes that make up the tops and bottoms of the unit cells is at =22.20. The wavelength of the X-rays is 1.54 A. What is the density of metallic gold?

Consider the three types of cubic units cells. (a) Assuming that the spherical atoms or ions in a primitive cubic unit cell just touch along the cubes edges, calculate the percentage of occupied space within the unit cell. (Recall that the volume of a sphere is (4/3)r3, where r is the radius of the sphere.) (b) Compare the percentage of occupied space in the primitive cell (pc) with the bcc and fcc unit cells. Based on this, will a metal in these three forms have the same or different densities? If different, in which is it most dense? In which is it least dense?

X rays of wavelength 2.63 were used to analyze a crystal. The angle of first-order diffraction (n = 1 in the Bragg equation) was 15.55 degrees. What is the spacing between crystal planes, and what would be the angle for second-order diffraction (n = 2)?

Lead has a face-centered cubic lattice with all atoms at lattice points and a unit-cell edge length of 495.0 pm. Its atomic mass is 207.2 amu. What is the density of lead?

How many tin atoms are contained in the tetragonal crystal lattice unit cell of -tin? How many tin atoms are contained in the cubic crystal lattice unit cell of -tin?

What is the coordination number of a chromium atom in the body-centered cubic structure of chromium?

Vanadium metal has a density of 6.11 g/cm3. Assuming the vanadium atomic radius is 132 pm, is the vanadium unit cell primitive cubic, body-centered cubic, or face-centered cubic?

The surface tension and viscosity of water at several different temperatures are given in this table. Water Surface Tension (mN/m) Viscosity (mPa s) 0 C 75.6 1.79 20 C 72.8 1.00 60 C 66.2 0.47 100 C 58.9 0.28 (a) As temperature increases, what happens to the surface tension of water? Explain why this occurs, in terms of molecular interactions and the effect of changing temperature. (b) As temperature increases, what happens to the viscosity of water? Explain why this occurs, in terms of molecular interactions and the effect of changing temperature.