Until the 1500s, doctors thought diseases were caused spontaneously. Scientists
began proposing that diseases were caused by
seed-like entities that could be passed among
people. After the invention of the microscope,
doctors came to know that many diseases were
actually caused by microscopic living organisms
like bacteria. What does this suggest about the
nature of scientific knowledge?-

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na