How many iron(ii) ions combine with oxygen to form iron(ii) oxide answer?

Iron (II) means that Fe has lost two electron i.e Fe⁺².

We also know that Oxygen normally exists in -2 oxidation state i.e. O⁻².

And, for a neutral Iron (II) Oxide the overall charge on it must be zero.

So,
                                    + 2 + (-2)  =  0
Means,
           For one atom of Fe⁺² we need one atom of O⁻².

                                                FeO

Result:
           One Iron (II) ion combines with oxygen to form iron(ii) oxide.

It’s the energy source of stars

Adozen is 12, and your needing to calculate the weight of one medium egg, so i would do 21/12=1.75 per egg, and check your answer by doing 1.75 * 12= 21 : ) : ): ): ): ) i hoped i