posted by Alex on .
Why does an iron ion attract a sulfide ion but not a zinc ion?
The iron ion and the zinc ion are positive and don't attract each other. The sulfide ion is negative and is attracted both to the iron ion and to the zinc ion.
Metal ions and non-metal ions always combine to form an ionic bond. Metals lose electrons to gain a fully filled outer shell to become stable and non-metals gain electrons to attain a full outer shell.
Iron ion has a charge of +2 or +3, which means depending on how many electrons it has in it's outer shell it loses those many electrons, Zinc on the other hand has a charge of +2 which means in a chemical reaction it will lose 2 electrons to form a positive 2 ion. Since both iron and zinc lose electron they are not attracted to each other.
Iron ion is attracted to sulfide ion because sulfide ion will gain the electrons lost by iron ion and form a negative ion, which means positive iron ion will be attracted to the negative sulfide ion and they will be held together by an electrostatic force of attraction.