What is Ionic Compounds and Covalent Compounds?
Chemical compounds are substances prepared by the chemical combination of two or more different elements. Chemical compounds are made up of molecules or ions that bond with each other via chemical bonds. The properties of compounds are distinct from both the properties of individual elements that make them and chemical and physical properties. This depends on the kind of chemical bond in such entities, and thus chemical compounds fall into a variety of types.
The two types of chemical compounds that are ionic and covalent compounds, differ in the nature of their bonding and therefore properties.
Ionic Compound
Ions in ionic compounds are held together by electrostatic forces of attraction. Ionic compounds are formed when all of an atom’s electrons are transferred to another atom. The atoms that lose their electrons become a cation, a positively charged ion; the atoms that gain electrons are a negatively charged ion called an anion. The oppositely charged ions are attracted to one another and combine to form an ionic compound.
Covalent Compound
A covalent compound is a chemical that occurs as a result of electron sharing between atoms. The atoms in such compounds have closely related differences in electronegativity, and they bond by sharing either one or more pairs of electrons. This shared pair of electrons forms a covalent bond that holds the atoms together in a molecule. Covalent compounds can be divided into two classes: nonpolar covalent compounds and polar covalent compounds, according to whether the difference in electronegativity values between atoms exceeds or does not exceed a certain limit.
Formation of Ionic Compounds and Covalent Compounds
Formation of Ionic Compounds
Such a bond would be produced between atoms if there existed a large electronegativity difference between the atoms. This is because the atom of greater electronegativity will pull the valence electrons of the other more closely and, therefore, strip off these electrons from the latter atom by complete electron transfer. The ionic compounds are produced through such an electron transfer between the atoms. Following the transfer of such electrons, electrostatic forces of attraction hold the cations and the anions together to form the ionic compound.
Example: The generally accepted common name for this ionic compound is table salt. It is formed by the transfer of an electron from an atom of the metal sodium (Na) to an atom of the nonmetal chlorine (Cl). It consists of positively charged ions called sodium cations (Na+) and negatively charged ions called chloride anions (Cl-), combined through electrostatic forces.
Formation of Covalent Compounds
Covalent bonds occur between atoms of comparable electronegativity values. The two electrons are shared between the atoms and allow them to attain a more stable electron configuration. They occupy the outermost energy levels, which is called valence shells. This shared pair of electrons allows for a stable electron configuration of both the atoms. It is called the covalent bond that holds the atoms together in a molecule.
Example: Water is a covalent compound with two hydrogen atoms, H and one oxygen atom, O. The hydrogen atoms share their electrons with the oxygen atom through covalent bonding and thus form a molecule of water.
Characteristics of Ionic Compounds and Covalent Compounds
The characteristics of Ionic Compounds and Covalent Compounds is given as:
Ionic Compounds:
- Ionic compounds are formed by the combination of a metal cation and a nonmetal anion.
- This compound has a high melting and boiling point due to strong forces of electrostatic attraction between the ions.
- Polar solvents, such as water, typically dissolve ionic compounds.
- Ions can conduct electricity because they are ionic in nature, either dissolved in water or in molten form.
- Typically ionic compounds have a three-dimensional crystal lattice structure.
Covalent Compounds:
- Typically covalent compounds consist of nonmetal atoms.
- These have lower melting and boiling points than ionic compounds.
- Covalent compounds tend to be soluble in nonpolar solvents.
- They do not carry electricity in any form since they lack freely moving charged particles.
- The bond energies of covalent bonds can vary considerably throughout a molecule, and even a given covalent bond can be different in strength.
Ionic Compounds and Covalent Compounds Difference
| Sr. No. |
Characteristics |
Ionic Compounds |
Covalent Compounds |
| 1 | Electron Behaviour | Electrons are transferred from one atom to another, forming ions. | Electrons are shared between atom. |
| 2 | Bond Type | Ionic bond, resulting in the formation of oppositely charged ions. | Covalent bonds, forming a shared electron cloud. |
| 3 | Solubility | Tend to be soluble in polar solvents like water. | Often soluble in nonpolar solvents. |
| 4 | Melting and Boiling Points | Higher melting and boiling points due to strong electrostatic forces. | Lower melting and boiling points compared to ionic compounds. |
| 5 | Electron Configuration | Achieves a noble gas electron configuration by transferring electrons | Achieves a stable electron configuration by sharing electrons |
| 6 | Strength | Generally stronger than covalent bonds | Can vary in strength |
| 7 | Conductivity | Can conduct electricity when dissolved in water or in a molten state. | Generally poor conductors of electricity. |
| 8 | Examples | Sodium chloride (NaCl), Calcium oxide (CaO) | Water (H2O), Methane (CH4) |
| 9 | Applications | Medicine, Construction Materials, Fertilizers | Organic Chemistry, Electronics and Semiconductors, Polymers and Plastics |
Summary
Ionic and covalent are the two major categories of compounds in chemistry. Ionic compounds are produced through the transfer of electrons from one atom to another, which thus gives them oppositely charged ions held together by strong electrostatic forces. Often, they have atoms of a large difference in electronegativity between them. Covalent compounds, on the other hand, take place through the sharing of electrons between atoms. Then, this leads to a shared electron cloud that would hold the atoms together. Most covalent compounds usually occur when the electronegativity between the atoms are similar.