Answer:
B) Photosynthesis is the process in which light energy is transformed into food energy.
1) The metal which reduces the other compound is the one higher in the reactivity. So in this case it is
.
2) The substance which brings about reduction while itself getting oxidised (that is losing electrons) is called a reducing agent. Here, $\mathrm{Zn}$ is the reducing agent and reduces Cobalt Oxide to Cobalt while itself getting oxidised to Zinc oxide.
Answer:5
Explanation:(H3) is 3 (H3)2 is 5