Ionic bonding
Learn about the basic structure of an ion, related to atomic number and mass.
Ionic bonds are formed between a metal and non-metal, for example sodium chloride.
An atom of sodium will lose an electron and form a positive ion.
An atom of chlorine will gain an electron and form a negative ion.
The ionic bond is the electrostatic force of attraction between a positively charged metal ion and a negatively charged non-metal ion.
Metals form positive ions because they lose electrons to become stable.
Example:
Magnesium (Mg) has the electron arrangement 2,8,2.
To become stable it must lose its two outer electrons to obtain a full outer energy level.
Atoms are neutral because they have equal numbers of protons and electrons however, when they lose two electrons they are no longer neutral. They change into ions with a two positive charge.
Non-metals form negative ions because they gain electrons to become stable.
Chlorine (Cl) has an electron arrangement 2,8,7.
To become stable it must gain an electron to obtain a full outer energy level.
When these two charged particles come together they form an ionic bond because the positive magnesium ion is attracted to the negatively charged chloride ion.
Ionic compounds form what is known as a lattice structure. This is a regular repeating arrangement of metal and non-metal ions which creates compounds with very high melting points which conduct when molten or in solution but never when solid.
Ionic compounds dissolve in water easily, when they do this their lattice breaks up completely and water molecules surround the seperated ions. Therefore they can conduct as their ions are free to move.
Ionic compounds, structures, bonding and properties.