1. Give the diffraction results in Table 1, figure out the X-ray wavelength used. 2. Figure out the lattice parameter a (the edge length of a unit cell) 3. Fill in values for the \"?" marks Table 1. X-ray diffraction data from a cubic compound, the D-spacing has a unit of Angstrom. (HKL) represents the Miller index for crystal planes. 2THETA INTENSITY DSPACING H K L 18.06 3.71 4.9127 1 l 1 29.70 35.85 3.0084 2 2 O 34.97 100.00 2.5656 ? ? ? 36.58 3.43 2.4563 2 2 2 42.50 18.42 2.1272 ? ? ? 52.70 11.94 1.7369 4 2 2 56.17 28.18 1.6376 5 1 1 56.17 5.72 ? 3 3 3 r4 fr n4 nn 4 r-Alln A A n