Ionic Compounds

Have you ever wondered what happens when metals and non-metals react? They form ionic bonds which form ionic compounds. An ionic bond is the electrostatic force of attraction between two oppositely charged ions. Let’s find out more about it.

Suggested Videos

What are ionic compounds?

Compounds that consist of ions are known as ionic atoms. Atoms that gain or lose electrons are called ions, ions may have a negative charge or positive charge. Nonmetals lose electrons to gain negative charge and form anions, whereas metals lose electrons to gain positive charge and form cations. Anions are ions that have negative charge and cations are ions that tend to have a positive charge. Ionic bonds are generally between metals and non-metals.

For e.g.  Salt (NaCl) is an ionic bond that consists of Sodium (Na) which is a metal with positive charge combines with Chlorine (Cl), a nonmetal with a negative charge. Another example of an ionic bond is Magnesium Hydroxide Mg(OH)2 which a combination of Magnesium (Mg) and Hydroxide (OH). Here, Magnesium is a metal with cations and Hydroxide is a nonmetal with anions. Iron Oxide (Fe₂O₃) also known as rust is also an ionic bond, it has metallic compound Iron (Fe) which contains positively charged cations and it has nonmetallic compound Oxygen (O) which contains negatively charged anions.

Browse more Topics under Metals And Nonmetals

• Physical Properties of Metals and Nonmetals
• Chemical Properties of Metals and Nonmetals
• Occurrence Of Metals
• Corrosion

Learn more about Physical Properties of Metal and Non-Metals here in detail.

Properties of Ionic Compounds

• Ionic Compounds have high boiling and melting points as they’re very strong and require a lot of energy to break.
• The electrostatic forces of attraction between oppositely charged ions lead to the formation of ions.
• Ionic compounds form crystals.
• These compounds are brittle and break into small pieces easily.
• Electrovalent compounds usually dissolve in water and are insoluble in solvents like oil, petrol, kerosene, etc.
• Ionic compounds do not conduct electricity in a solid-state but they do conduct electricity in the molten state.
• In comparison to molecular compounds, ionic compounds have higher enthalpies of fusion and vaporization.

Download Ionic Compounds Cheat Sheet PDF

Formation of Ionic bond

There is only one electron in the outermost shell of Sodium (Na) atom and if it loses that electron from its outermost shell i.e. the M shell then the L shell becomes the outermost shell and it has a stable octet. There are eleven protons in the nucleus of this atom but the number of electrons has become ten, this gives the sodium atom a positive charge and creates a sodium cation Na⁺. Whereas, on the other hand, there are seven atoms in the outermost shell of the Chlorine (Cl) atom then it needs one more electron to complete its octet.

Learn more about Corrosion here in detail.

If Sodium and Chlorine reacted then the electron lost by sodium would be taken by Chlorine. After this process, the chlorine atom would have a negative charge, because it would have seventeen protons in its nucleus and there would be eighteen electrons in its K, L and M shells. This gives the Chlorine atom a negative charge. Hence, the negatively charged Chlorine and positively charged Sodium creates an Ionic bond or an Electrovalent compound.

Learn more about the Occurrence of Metals here.

Solved Example for you :

Q: State whether the following statement is true or false. Sodium Chloride has a higher melting point than Magnesium Oxide. Justify your answer.

Ans.  The following statement is True. Magnesium Oxide (MgO) has a higher melting point than Sodium Chloride (NaCl) which is around 2,800 degrees Celcius. This is because its Mg²⁺ and O^2- ions have a greater number of charges, and so form stronger ionic bonds, than the Na⁺ and Cl^– ions in Sodium Chloride. Because it stays solid at such high temperatures, magnesium oxide remains non-conductive and is used for high temperature electrical insulation.