Ionic Bonding

To begin, let us define the term “ions.” The positive and negative charged electrons are known as ions. Cations have a positive charge, while anions have a negative charge. Ionic bonding is a form of bonding in which both cations and anions are bound together.

History of Ionic bonding

The concept of ionic bonding had been rapidly increased, but how actually the concept of ionic bonding had been discovered.

The concept of ionic bonding evolved slowly over the years.

The scientist named  Michael Faraday, Conducted an experiment called electrolysis. The method of electrolysis showed that some substances would produce an electric current when dissolved in water.

Electrolysis: Electrolysis is the process in which electric current is used to perform the oxidation and reduction process.

He thought that breakage in charged substances is due to electricity. And then he named those charged particles as anion(Negatively charged ions) and cation(Positively charged ions). Svante August Arrhenius defined an ion as an atom with a positive or negative charge in 1884.

J. J. Thomson demonstrated in 1897 that cathode rays are streams of free electrons.

He believed that electrons had a role in bonding and even hypothesised that the atoms in HCl are connected by an electromagnetic “tube” (the term “bond” had not yet been coined).

He proposed that HCl had two ends, one positive and one negative.

Wilhelm Wien demonstrated in 1898 that the e/m ratio of canal rays was affected by the gas in the discharge tube.

He demonstrated that positive charges (unlike electrons) could not be transmitted from one atom to another, implying that bonding could not occur.

Theories of ionic bonding and electron transfer have advanced quickly since then.

Ionic bonding definition:

Ionic bonding is a type of chemical bond, where the transfer of electrons takes place between two opposite charges because oppositely charged particles attract each other due to electrostatic forces.

Ionics bonds are really strong bonds.

In an ionic bond, One atom loses or donates its electrons to obtain stability and one atom gains or accepts electrons to obtain stability.

The best example of ionic bonding is Sodium chloride, Calcium oxide etc.

Examples of ionic bond

Now, let us look into the sodium chloride example, Sodium is positively charged and chlorine is negatively charged.

Now let us understand step-by-step, to know how this ionic bonding actually works with the NaCl example.

Formation of Sodium chloride

• Sodium is a metal and chlorine is a non-metal with zero charge

• Sodium gives electrons to chlorine to obtain stability

• Since sodium lost electrons, it gets positive(+) charge and chlorine gains electrons it gets negative charge(-)

• Now chlorine has one electron, so it now changes into chloride form.

• These oppositely charged electrons are attracted due to electrostatic forces of attraction.

The above diagram would clearly explain the ionic bonding process. The atomic number of sodium is 11 and has 11 electrons and 11 protons. The atomic number of chlorine is 17 and has 17 electrons and 17 protons.

At the outermost shell, sodium has only one electron but Chlorine needs one electron to obtain octet rule or to fill its outermost shell.

So, now sodium loses its electrons and gives it to chlorine. So that chlorine will fill its outermost shell.

Transfer of electrons is done between sodium and chlorine.

Now, sodium has ten electrons and eleven protons.So it gets positive charge(Na+).And chlorine has 18 electrons and 17 protons, so chlorine gets negative charge(Cl-).

Na + Cl → Na+ + Cl− → NaCl

Characteristics of ionic bonding

• The ionic substances, in general, have a crystalline form. They are made up of positively and negatively charged ions bound together in a crystal lattice by electrostatic forces of attraction. Sodium chloride is an example.

• Melting and boiling points are quite high. – Because the ions are held together by strong electrostatic forces of attraction, the electrovalent compounds have high melting and boiling temperatures.

Conclusion

Ionic compounds have a lattice structure. Ionic bonding is a transfer of ions or electrons between metals and nonmetals. Metals are electron givers and non metals are electron takers. The word ion actually derived from the Greek word. Transfer of electrons is done between two opposite charges. Electrostatic forces of attraction take place between them.