Which one of the following is the correct order of reactivity of Mg, Al, Zn and Fe with HCl?

Which one of the following is the correct reactivity series with water?

Which one of the following is the correct arrangement of metals in the decreasing order of their reactivity?

Which one of the following is the highest reactive metal?

Which of the following is not correctly matched?

Which one of the following is the correct sequence of the given substances in the decreasing order of their densities?