Аннотация:Photonuclear reactions on a natural mixture of mercury isotopes were investigated by the activation method at an electron energy of Em = 55 MeV. The reaction yields as well as the isomeric ratios for 195,197Hg and 198,200Au were determined. The obtained results are compared with theoretical predictions from the TALYS 2.0 code. Based on both the present experimental and available literature data, the systematics of isomeric ratios as a function of spin factors were obtained for heavy nuclei in the Z = 60−80 range.