Which statement about an atom is true ? 1. all the elements have only one nucleon (mass) number.
2. the nucleon (mass )number can be less than the proton (atomic) number.
3. the nucleon (mass) number can equal the proton (atomic) number.
4. the number of neutrons never equals the number of electrons.

just did the assignment and the answer was #1 +2 n

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