a) Zn → ZnO → Zn(NO₃)₂ → Zn(OH)₂ → ZnO → ZnCl₂

The image shows a chemical reaction sequence starting with Zinc (Zn). The sequence indicates transformations of Zinc through various compounds: Zinc Oxide (ZnO), Zinc Nitrate (Zn(NO₃)₂), Zinc Hydroxide (Zn(OH)₂), and finally Zinc Chloride (ZnCl₂). The numbers above the arrows likely represent reaction conditions or steps, but without further context, they are not interpretable as a solvable problem. The text '1,6-6BP, 2,3-ионное' below the reaction sequence appears to be additional data or labels related to the reactions, possibly indicating quantities or types of bonding, but it does not form a complete question.