The model below shows an atom of an element.

what is the atomic number of this atom?

6
8
9
16

The the atomic number of this atom is 8.

Explanation: The particles with zero charge represents neutrons, The particles with negative charge represents electrons and the particles with positive charge represents protons.

The number of particles with negative charge are eight in number, thus there are eight electrons. The number of particles with positive charge are eight in number, thus there are eight protons. Thus it is a neutral atom.

The number of electrons represent the atomic number for a neutral atom. Thus the element has atomic number of 8.

catya your not at all which answer i've seen you do this on another question!

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