Energy bands are considered continuous due to the large number of closely spaced energy levels. The range of energy levels in a crystal of copper is approximately 1 X 10−−19J. Assuming equal spacing between levels, the spacing between energy levels may be approximated by dividing the range of energies by the number of atoms in the crystal.
a. How many copper atoms are in a piece of copper metal in the shape of a cube with edge length 0.5 mm? The density of copper is 8.96 g/cm3.
b. Determine the average spacing in J between energy levels in the copper metal in part (a).
c. Is this spacing larger, substantially smaller, or about the same as the 1 X 10−−18 J separation between energy levels in a hydrogen atom?
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Chapter 12 Solutions
Laboratory Experiments For Chemistry: The Central Science, Si Edition
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- If one edge of the silicon carbide unit cell is 436.0 pm, what is the calculated density of this compound? (a) 0.803 g/cm3 (b) 0311g/cm3 (c) 321 g/cm3arrow_forwardClassify each substance in the table as either a metallic, ionic, molecular, or covalent network solid: Substance Appearance Melting Point Electrical Conductivity Solubility in Water X brittle, white 800 C only if melted/dissolved soluble Y shiny, malleable 1100 C high insoluble X hard, colorless 3550 C none insolublearrow_forwardIdentify the kinds of forces that are most important in holding the particles together in a crystalline solid sample of each of the following substances. (a) Kr (b) HF (c) K2O (d) CO2 (e) Zn (f) NH3arrow_forward
- • describe the arrangement of atoms in the common cubic crystal lattices and calculate the packing efficiency for a lattice.arrow_forwardMnO has either the NaCI type structure or the CsCI type structure (see Exercise 69). The edge length of the MnO unit cell is 4.47 10-8 cm and the density of MnO is 5.28 g/cm3. a. Does MnO crystallize in the NaCl or the CsCl type structure? b. Assuming that the ionic radius of oxygen is 140. pm, estimate the ionic radius of manganese.arrow_forwardThe specific heat capacity of silver is 0.235 J/g K. Its melting point is 962 C, and its enthalpy of fusion is 11.3 kJ/mol. What quantity of energy, in joules, is required to change 5.00 g of silver from a solid at 25 C to a liquid at 962 C?arrow_forward
- Describe the unit cell of lithium (see Figure).arrow_forward8.13 What is the coordination number of atoms in the diamond structure?arrow_forwardConsider 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?arrow_forward
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