Determine the Atomic Packing Factor (APF) of a base-centered tetragonal crystal structure shown below. In this structure, atoms are touching along the base diagonal. The height of the unit cell is given by c and is equal to 1.71 times a. Express your answer in terms of percentage and in two decimal places only. Do not put the percentage sign.

Which would you predict to have a higher melting point, SiO2 or CO2? Why? Please list the actual melting point values. Did your prediction agree Yes or No?

Kristen Mcku The Packing of Atoms and Ions in Crystals Note: Please put all the answers in decimal form. Assume the radius of each sphere = 1.00 A. 1. A Study of Metallic Crystals a. Body-Centered Cubic Why is this structure called body-centered cubic? Because the one carbon atom is the center of the cube. What is the coordination number of a sodium atom when packed in a crystal of this type? If this model were extended in all directions, what difference, if any, would there be in the relative position of corner sphere and those in the center? Note: In the calculations below, consider all distances to be measured between the centers of the spheres. From a study of the right triangles involved in a cube, as illustrated below, where (a) is the edge length. (f) is the face diagonal, and (b) is the body diagonal, the following is apparent: a 711 b b² = f² + a² f = a² + a² b² = 3a² In calculating the volumes, not that only one-eighth of each of the corner spheres is inside the cube which…

The unit cell of strontium titanate SrTiO3 is depicted on the left in the figure below showing the crystal structure as confirmed by X-ray diffraction experiments. The lattice constant is a - 3.9 × 10-¹0 m. A typical X-ray powder diffraction spectrum is displayed on the right. The wave length of the X-ray beam (Cu-Ka radiation) is λ = 1.54 × 10-¹⁰ m. Unit cell of SrTiO3; Sr atoms are shown in blue, Ti in black and the oxygen atoms are in red. Normalized intensity (a.u.) (001) 20 (011) 30 (III) 40 (200) (210) 50 (211) (220) (300) 60 20 (degrees) 70 (310) (311) >(222) (320) 80 90 (17) 100 X ray powder diffraction data for SrTiO3; the plot shows an overlay for two different SrTiO3 samples. [L. da Silva et al, J. Nanomat., doi:10.1155/2012/890397] a) Identify the Bravais lattice of SrTiO 3and specify the basis for the primitive unit cell shown in the figure. b) Explain how the Miller indices (hkl) describe a family of lattice planes. State a set of possible reciprocal lattice vectors. c)…

Part A The unit cells for lithium oxide and silver iodide are shown below (Figure 1). Show that the ratio of cations to anions in the unit cell of Li,0 corresponds to the ratio of cations to anions in the formula of the compound. Match the numbers in the left column to the appropriate blanks in the sentences on the right. Reset Help 1 The Li atoms occupy position(s) inside the unit cell, giving 2 Li atom(s)/unit cell. 3 Figure < 1 of 1 The O atoms occupy corner 4 position(s) and face-center 5. position(s) of the unit cell, giving O atom(s)/unit cell. The ratio of Li :0 atoms is 8 which reduces to 10