Iron has a body-centered cubic structure with a density of 7.86 g cm-3.(a) Calculate the nearest neighbor distance in crystalline iron.(b) What is the lattice parameter for the cubic unit cell of iron?(c) What is the atomic radius of iron?

(b) Many structures of ionic compounds have been described in terms of close packing of a large anion, X, with a cation, A, occupying tetrahedral or octahedral holes. (1) In a cubic close packed lattice, how many octahedral holes are there per lattice ion? (ii) What is the formula of a compound based upon a cubic close packed lattice in which of the octahedral holes are filled? (ii) State the coordination numbers and geometries of A and X In the crystal lattice in part (b)(ii) above.

Calcium crystallizes in a face-centered cubic unit cell atroom temperature that has an edge length of 5.588 Å.(a) Calculate the atomic radius of a calcium atom. (b) Calculatethe density of Ca metal at this temperature.

At a certain temperature and pressure an element has the simple body-centred cubic unit cell, depicted below. The corresponding atomic radius is 2.659 Å and the density is 1.907 g cm-3. Calculate (and enter) the atomic mass for this element (in amu).

The P=T phase diagram of iron(Fe) is shown below, where the - Fe and -Fe phases are in body-centered cubic(bcc) structure, while the - Fe is in Face-centered cubic(fcc) structure. (a) Draw schematic G-T diagrams of Fe at 1 and 10^-8 atm and the G-P diagram at 1500 C. (b) Please draw schematic H-T and S-T diagrams of Fe at 1 atm. (d) Please draw schematic G-T and G-P diagrams of Fe at the fcc-liquid-Vapor triple point. (e) Please estimate the enthalpy change and entropy change of one mole of Fe being heated from 30 to 1500 °°℃. (f) Please estimate the enthalpy changes of one mole of fe under the → phase transformation at 500 and 1200 °C. (e) Please calculate the heat of evaporation of Fe at the normal boiling temperature. (h) Please explain why the phase boundaries of,, and /liquid equilibria are much steeper than those with the vapor phase in the phase diagram. Note: Please make sure the slopes and curvatures are with physical meanings

(a) Magnesium (Mg) has a hexagonal close-packed (HCP) crystal structure with the lattice parameter of a = 0.321 nm and c= 0.521 nm and the atomic radius is 0.173 nm. (i) What is the number of atoms per unit cell in HCP structure? (ii) Determine the atomic packing factor of the Mg unit cell. (iii) Is Mg containing an ideal atomic packing factor? You may justify your answer by evaluating the HCP c/a ratio. Subsequently, will slip be harder in Mg compared to the ideal HCP structure? Justify your answer.

1. The co-ordination number of metal crystallizing in a hexagonal close packed structure is (a) 12 (b) 4 (c) 8 (d) 6

a) A hexagonal close-packed layer in two dimensions is shown in figure 2.By identifying a suitable unit cell, calculate the packing fraction of this structure.

(a) The unit cells of three structural types of ionic solids are shown below (the anions appear light and the cations dark). The anions occupy the lattice positions. X (B) (A) (i) Name the common structural type for (A), (B) and (C). (Hint: a typical structural type is rutile (T1O₂).] (C) (ii) The structures (A), (B) and (C) can be considered as packing of anlons with the cations occupying specific types of hole. For each structure: state the unit cell that the packing of anions is based on. state which holes are occupied by the cations and what fraction of them are occupied. State the coordination numbers of the cations and anions for (A), (B) and (C).

(a) A hypothetical compound MB2 crystallises in the rutile lattice structure. (i) Draw the lattice structure of the unit cell MB2. (ii) Show by calculation that the stoichiometry of the formula is consistent with the structure. (iii) Determine the coordination number of the MB₂ unit cell.