Thin films of Na with Fe, Co, and Ni impurities are investigated. The magnetization of the impurities is measured by means of the anomalous Hall resistance. Fe and Co show a moment of about 6μB, while for Ni no moment is detected. Furthermore, the magnetic dephasing of the conduction electrons is measured by means of weak localization. The dephasing rate 1/τφ of the 3d impurities differ qualitatively. For Fe impurities, 1/τφ is so large that it cannot be measured. For Co, 1/τφ has a moderate value while Ni shows hardly a dephasing effect at all.