A "double-hump" pattern and a systematic trend of adsorption energies of the first-row transition metal atoms (Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn), adsorbed on the surface of silicon dioxide, has been revealed by all-electron density functional theory (DFT) calculations. The study employs periodic DFT at the full-potential linearized augmented plane wave (FP-LAPW) level with spin-polarization taken into account, The geometry of the adsorbed atoms and the silica surface is optimized. The double-hump dependence of the neutral metal adsorption energy on the number of d electrons is reminiscent of the ligand field stabilization energy (LFSE) pattern for ions, but superimposed on it are significant contributions involving 4s electrons of neutral atoms. As a result, the overall trend for neutral atoms is to decrease adsorption strength (or adhesion) with increasing atomic number on top of the Ar closed shell, and this trend is opposite to that of ions that are bonded with increasing strength as the number of electrons in the [Ar]3d(n)4s(1-2) series increases.