Why is our use of electric power increasing?

i just got this problem. it's 90.3

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

the answer is d.) potassium

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l