What is the hydrogen ion concentration of a solution with ph = 8.25?

You just need to know that pH is the logarithm of the inverse of the concentration of hydrogen ion.

Mathematically this is: pH = log { 1/[H+] }

Then if you know the pH you can find [H+] using the properties of the logarithm function.

=> pH = - log [H+] => [H+] = 10^(-pH)

=> [H+] = 10 ^(-8.25) = 5.62 * 10^-9

the concentration of hydrogen ion, [H+], is 5.62 * 10^-9 M

Idk the answer sorry

The total number of electrons is 14