Can someone please help me please?

option no B

Explanation:

hope helps you

the weighted average of the masses of the isotopes of the element.

Explanation:

every element has siblings, which are called isotopes. Isotopes are an element that has the same amount of protons and electrons, but it's mass is different because it has a different amount of neutrons.

the atomic mass is the average of all of those isotopes.

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