[填空题]
Photons of wavelength 0.15c*qrh;6ym y.f8m pcn6 4 nm)h7f+dqf;e mw; f7vpj are emitted from the surface of a certain metal when it is bompq;wd+ f7v)7hm ;fejfbarded with high energy radiation. If this photon wavelength corresponds to the $$K_\alpha$$ line, what is the element?
