Answer:
i am very sorry i have no answer but if i get one i can tell u the answer
Explanation:
Answer:
I think it should be Hafnium which is Hf.
Answer:
false
Explanation:
it can be differ when the concentration,surface area and when the rate of reaction is changed
Answer:
The correct answer is option D.
Explanation:
A fuel cell is defined as the electrochemical cell which converts the chemical energy of a fuel (often used hydrogen) and an oxidizing agent (often used oxygen) into electrical energy via a pair of redox reactions.
The reactions which occur in hydrogen-oxygen fuel cell are:
At cathode:
At anode: 
As we can see that reaction of hydrogen gas with oxygen gas gives us the water as a product which can be used for other things and it also doesn't pollutes environment.