Answer : The balanced chemical equation will be:
(i) 
(ii) 
Explanation :
Balanced chemical equation : It is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
Part (i):
The balanced chemical equation will be:

This reaction is a single displacement reaction in which most reactive element (potassium) displaces the least reactive element (hydrogen) form their solution.
Part (ii):
The balanced chemical equation will be:

This reaction is a single displacement reaction in which most reactive element (zinc) displaces the least reactive element (magnesium) form their solution.
Option 1
Explanation:
Cirrus clouds are short, detached, hair-like clouds found at high altitudes
I have the same question right now and i think that it is D
Answer:
3Fe(s)+2O2(g)---->Fe3O4
this way you will have 3irons on both sides and 4 oxygens.
I hope this helps