Determine d-spacing and radius from a scattering angle. Tantalum metal crystallizes in a body-centered cubic lattice with one atom per lattice point. Monochromatic X-radiation from a Mo target has a wavelength of 71.07pm. If this radiation is used in a diffraction experiment with a tantalum crystal, a second order diffracted beam is observed at a theta value of 12.43. If the spacing between these planes corresponds to the unit cell length (d=a ), what is the d-spacing between the planes that gave rise to this reflection? What is the metallic radius of a tantalum atom? dsppacing=radius=pmpm