[单选题]
High-energy photons arenm-yvovu.ghd32 g2tp 3tux- . xuv;*c3;k(bqb/lk gwvq*e)c+.ot cq used to bombard an unknown metal. The strongest peak is found for X-rays with an energy of 66 keV. What is the atl+kx*bt oq /w)cgq cvq*.ek v;(b;c3uomic number of the metal?
