At 100°C copper has a crystallographic radius of 1.57 Å and a lattice constant of 3.655...
α-Co has an hcp structure with lattice spacing of a = 2.51 Å and c = 4.07 Å; β-Co is fcc, with a cubic lattice spacing of 3.55 Å. What is the difference in density between these two forms of Co? 0 % 10 % 14.1 % 41.4% Cannot be determined
Iron crystallizes in a bcc structure, with a lattice constant of 2.8685 Å. a)Find the atom density (number of atoms per cm2) for iron in the (100) plane b) Find the atom density for iron in the (011) plane
2. ZrO2 crystallizes in the fluorite structure. (a) Calculate the crystallographic density of ZrO2, if the lattice parameter is 5.26 Å. (b) You have prepared a ZrO2 sample in the lab and measure its gravimetric density to be 5.25 g/cm2. What percent of your sample is porous?
6. (a) Calculate the density of GaAs (the lattice constant of GaAs is 5.65 Å, and the atomic weights of Ga and As are 69.72 and 74.92 g/mol, respectively). (b) A gallium arsenide sample is doped with tin. If the tin displaces gallium atoms in crystal lattice, are donors or acceptors formed? Why? Is the semiconductorn- or p-type?
Aluminum (Al) has FCC unit cell geometry and lattice parameter 4.0 Å. a. How many complete atoms are contained in one unit cell? b. What is the atomic radius (Å)? c. What is the unit cell volume? d. If the atomic mass of Al is 27 grams per mole (or amu), what is an Al atom’s mass in grams? e. What is the mass of the unit cell? f. What is the density of Al in units of atomic mass...
Question 2. A primitive tetragonal crystal has lattice parameters of a=b=3 Å and c=4 Å and is placed in an x-rays powder diffraction system and irradiated with X-rays of wavelength 2.5 Å. (i) Use Bragg’s law to determine the scattering angle for the (001), (100), and (111) reflections (n=1). (ii) Is it possible in this apparatus to observe the (111) reflections from this crystal using X-rays of wavelength 5 Å.? Why not?
The atom radius of copper is r = 0.1278 nm. Its crystal structure has face-centered cubic cells. a) What is the crystal-lattice constant? b) What is the concentration of copper atoms? c) What is the atomic volume (the volume of 1 mol of copper)? answer each part with explanation and shown work
1.A copper cylindrical wire which has a radius of 1.2 * 10 -3m carries a constant current of 6.0 A. Assume each copper atom contributes one free electron. The density of copper is 8.93 g/cm3. Calculate the following: a.Drift velocity, vD, (m/s) b.Resistance (Ω) of a 2 meter segment of this wire at room temperature You will need to look up the following: 1. molar mass of copper, 2. resistivity of copper @ room temp, 3. Avogadro’s number
*11-1 The lattice parameter of copper is to be determined to a precision of +0.0001 A at 20°C. Within what limits must the temperature of the specimen be controlled if errors due to thermal expansion are to be avoided? The linear coefficient of thermal expansion of copper is 16.6 x 10-6 per °C.
Calculate the critical radius (in centimeter) of a homogeneous nucleus that forms when pure liquid copper solidifies. Assume Delta T (under cooling) =0.2T_m. Where T_m=1083 degree C. Values for the latent heat of fusion and surface free energy are 1826 J/cm^3 and 177 times 10^-7 J/cm^2, respectively. Calculate the number of atoms in the critical sized nucleus at this under cooling. Copper has FCC crystal structure. Assume a lattice parameter of 0.361 nm for solid copper at its melting temperature