Difference Between Ionic Covalent and Metallic Bonds

Main Difference – Ionic vs Covalent vs Metallic Bonds

Bonds can be divided into two broad categories; primary bonds and secondary bonds. Primary bonds are the chemical bonds that hold atoms in molecules, whereas secondary bonds are the forces that hold molecules together. There are three types of primary bonds namely ionic bonds, covalent bonds, and metallic bonds. Secondary bonds include dispersion bonds, dipole bonds, and hydrogen bonds. Primary bonds have relatively high bond energies and are more stable when compared with secondary forces. The main difference between ionic covalent and metallic bonds is their formation; ionic bonds form when one atom provides electrons to another atom whereas covalent bonds form when two atom shares their valence electrons and metallic bonds form when a variable number of atoms share a variable number of electrons in a metal lattice.

This article examines,

1. What are Ionic Bonds?
       – Definition, Formation, Properties

2. What are Covalent Bonds?
       – Definition, Formation, Properties

3. What are Metallic Bonds?
       – Definition, Formation, Properties

4. What is the difference between Ionic Covalent and Metallic Bonds?Difference Between Single Ionic Covalent and Metallic Bonds - Comparison Summary

What are Ionic Bonds

Certain atoms tend to donate or receive electrons in order to become more stable by completely occupying their outermost orbit. Atoms with very few electrons in their outermost shell tend to donate the electrons and become positively charged ions, while atoms with more electrons in their outermost orbit have a tendency to receive electrons and become positively charged ions. When these ions are brought together, the attraction forces are occurred due to opposite charges of ions. These forces are called ionic bonds. These stable bonds are also called electrostatic bonds. Solids bonded with ionic bonds have crystalline structures and low electrical conductivity, which is due to lack of free moving electrons. Bonds usually occur between metal and non-metal that are having a large difference in electronegativity. Examples of ionically bonded materials include LiF, NaCl, BeO, CaF2 etc.Difference Between Ionic Covalent and Metallic Bonds - 1

What are Covalent Bonds

Covalent bonds are formed when two atoms share their valence electrons. The two atoms have a small difference in electronegativity. Covalent bonds occur between same atoms or different types of atoms. For example, fluorine needs one electron to complete its outer shell, thus, one electron is shared by another fluorine atom by making a covalent bond resulting F2 molecule. Covalently bonded materials are found in all three states; i.e., solid, liquid and gas. Examples of covalently bonded material include hydrogen gas, nitrogen gas, water molecules, diamond, silica etc.  Difference Between Ionic Covalent and Metallic Bonds

What are Metallic Bonds

In a metal lattice, valence electrons are loosely attached by the nuclei of metal atoms. Thus, valence electrons require very low energy to release themselves from nuclei. Once these electrons detach, metal atoms become positively charged ions. These positively charged ions are surrounded by a large number of negatively charged, free moving electrons called an electron cloud. Electrostatic forces are formed due to the attractions between the electron cloud and ions. These forces are called metallic bonds. In metallic bonds, almost every atom in the metal lattice shares electrons; so there is no way to determine which atom shares which electron. Because of this reason, electrons in metallic bonds are referred to as delocalized electrons. Due to the free moving electrons, metals are known for good electricity conductors. Examples of metals with metallic bonds include iron, copper, gold, silver, nickel etc.Main Difference - Ionic vs Covalent vs Metallic Bonds

Difference Between Ionic Covalent and Metallic Bonds

Definition

Ionic bond: Ionic bonds are electrostatic forces arising between negative and positive ions.

Covalent bond: Covalent bonds are bonds that occur when two elements share a valence electron in order to get electron configuration of neutral gasses.

Metallic bond: Metallic bonds are forces between negatively charged freely moving electrons and positively charged metal ions.

Bond Energy

Ionic Bonds: Bond Energy is higher than metallic bonds.

Covalent Bonds: Bond Energy is higher than metallic bonds.

Metallic Bonds: Bond Energy is lower than other primary bonds.

Formation

Ionic Bonds: Ionic bonds form when one atom provides electrons to another atom.

Covalent Bonds: Covalent bonds form when two atom shares their valence electrons.

Metallic Bonds: Metallic bonds form when a variable number of atoms share a variable number of electrons in a metal lattice.

Conductivity

Ionic Bonds: Ionic bonds have a low conductivity.

Covalent Bonds: Covalent bonds have a very low conductivity.

Metallic Bonds: Metallic bonds have very high electrical and thermal conductivity.

Melting and Boiling Points

Ionic Bonds: Ionic bonds have higher melting and boiling points.

Covalent Bonds: Covalent bonds have lower melting and boiling points.

Metallic Bonds: Metallic bonds have high melting and boiling points.

Physical State

Ionic Bonds: Ionic bonds only exist in the solid state.

Covalent Bonds: Covalent bonds exist in the form of solids, liquids, and gasses.

Metallic Bonds: Metallic bonds exist in the form of solid only.

Nature of Bond

Ionic Bonds: The bond is non-directional.

Covalent Bonds: The bond is directional.

Metallic Bonds: The bond is non-directional.

Hardness

Ionic Bonds: Ionic bonds are hard due to the crystalline structure.

Covalent Bonds: Covalent bonds are not very hard with the exception of diamond, silicon, and carbon.

Metallic Bonds: Metallic bonds are not very hard.

Malleability

Ionic Bonds: Materials with ionic bonds are not malleable.

Covalent Bonds: Materials with covalent bonds are not malleable.

Metallic Bonds: Materials with metallic bonds are malleable.

Ductility

Ionic Bonds: Materials with ionic bonds are not ductile.

Covalent Bonds: Materials with covalent bonds are not ductile.

Metallic Bonds: Materials with metallic bonds are ductile.

Examples

Ionic Bonds: Examples include LiF, NaCl, BeO, CaF2 etc.

Covalent Bonds: Examples include hydrogen gas, nitrogen gas, water molecules, diamond, silica etc.

Metallic Bonds: Examples include iron, gold, nickel, copper, silver, lead etc.

References:

Cracolice, Mark. Basics of Introductory Chemistry with Math Review. 2nd ed. N.p.: Cengage Learning, 2009. Print.
Duke, Catherine Venessa. A., and Craig Denver Williams. Chemistry for Environmental and Earth Sciences. N.p.: CRC Press, 2007. Print.
Garg, S. K. Comprehensive Workshop Technology. N.p.: Laxmi Publications, 2009. Print.
 
Image Courtesy:
“Ionic Bonds” By BruceBlaus – Own work (CC BY-SA 4.0) via Commons Wikimedia
“Covalent Bonds” By BruceBlaus – Own work (CC BY-SA 4.0) via Commons Wikimedia
“Metallic bonding” By Muskid – Own work (CC BY-SA 3.0) via Commons Wikimedia
 

About the Author: Yashoda

Yashoda has been a freelance writer in the field of biology for about four years. He is an expert in conducting research related to polymer chemistry and nano-technology. He holds a B.Sc. (Hons) degree in Applied Science and a Master of Science degree in Industrial Chemistry.

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