Question 1. MATE 201 Aluminum foil used for storing food weighs about 465 g/m2. How many aluminum atoms are present in one square centimetre of foil? Fall 2014 Homework #1 Question 2. What are the main differences between ionic, covalent, and metallic bonding? D date: Due d t October O t b 20th, 2014 ((lecture time)) No late submissions! Your homework submission should have a cover page which contains th following the f ll i information; i f ti your name, student number, course name, homework number and date of submission. 1 2 Question 3. The interatomic spacing versus potential energy curves of two different hypothetical elements, a and b, are described in the figure below. below a. Which element has the higher melting temperature? b. Which has the larger g interatomic spacing p g at 0 Kelvin? c. Which element has the higher coefficient of thermal expansion? Briefly justify your answers. Question 4. Compute the percentage ionic character of the interatomic bond for each of the following compounds: CsF, CdS, and FeO. Question 5. Calculate the radius of a nickel atom (in nm), given th t Ni has that h an FCC crystal t l structure, t t a density d it off 3 8.91 g/cm , and an atomic weight of 58.71 g/mol. 3 4 Question 7. Question 6. The unit cell for uranium has orthorhombic symmetry, with a, a b, b and c lattice parameters of 0.286, 0 286 0.587, 0 587 and 0.495 nm, respectively. If its density, density atomic weight, weight and atomic radius are 19.05 g/cm3, 238.03 g/mol, and 0.1385 nm, respectively, compute the atomic packing factor. Show that the ideal c/a ratio is 1.633 for the HCP y structure. crystal 5 6 Question 9. Question 8. Within a cubic unit cell, sketch the following directions Sketch the following planes within a cubic unit cell : 7 8 Question 10. Within a hexagonal unit cell, sketch the following directions. 9 Question 11. Sketch the cell. and planes in a hexagonal unit 10