Short Answer

Bonding explains conductivity by showing how electrons move within a substance. In metals, metallic bonding creates a “sea of electrons” that can move freely, allowing electric current to pass easily. This makes metals good conductors.

In ionic compounds, conductivity depends on whether ions are free to move. They do not conduct electricity in solid form, but when melted or dissolved in water, their ions become mobile and allow conduction. Covalent compounds usually lack free electrons or ions, so they conduct poorly. Thus, bonding directly controls how well a substance conducts electricity.

Detailed Explanation :

Bonding and Conductivity

The ability of a substance to conduct electricity depends on the presence and movement of charged particles, such as electrons or ions. Different types of chemical bonding—metallic, ionic, and covalent—control how these charged particles behave inside materials. Therefore, understanding bonding helps explain why some substances conduct electricity easily, while others do not conduct at all.

Each bonding type creates a unique internal structure. In some structures, electrons are free to move, making the material a good conductor. In other structures, electrons are tightly held, preventing movement and resulting in poor conductivity. The physical state of the substance, such as solid, liquid, or solution, also affects conductivity. By examining bonding, we can understand why metals, ionic compounds, and covalent compounds show very different electrical behaviors.

1. Conductivity in Metallic Bonding

Metallic bonding is the main reason metals conduct electricity. In this type of bonding:

• Metal atoms release some of their electrons.
• These electrons do not stay attached to any one atom.
• They move freely throughout the entire metal structure.

This free movement forms what is often described as a sea of electrons. Because electrons carry charge, their ability to move freely allows metals to conduct electricity very well. When a voltage is applied, these electrons flow from one end of the metal to the other, creating electric current.

Key points:

• Metals conduct in both solid and liquid states.
• Conductivity depends on electron mobility.
• Alloys may show slightly lower conductivity because impurity atoms can hinder electron flow.

Thus, metallic bonding perfectly explains why metals such as copper, aluminium, gold, and silver are excellent conductors.

2. Conductivity in Ionic Bonding

Ionic compounds behave differently because they consist of positive and negative ions held together by strong electrostatic forces. In solid form:

• The ions are fixed in a rigid lattice.
• They cannot move freely.
• Therefore, solid ionic compounds do not conduct electricity.

However, when an ionic compound is melted or dissolved in water:

• The ionic lattice breaks apart.
• The ions become free to move.
• These free-moving ions carry electric charge.

As a result, molten ionic compounds and aqueous ionic solutions conduct electricity very well.

Examples:

• Molten NaCl conducts electricity.
• NaCl solution in water also conducts.

Thus, ionic bonding explains conductivity based on ion mobility rather than electron movement.

3. Conductivity in Covalent Bonding

Covalent compounds generally do not conduct electricity. This is because:

• They have no free electrons.
• They do not produce ions.
• The electrons in covalent bonds are tightly shared between atoms.

Examples such as sugar, water, methane, and plastic do not conduct electricity under normal conditions.

However, there are exceptions:

• Graphite, a form of carbon, conducts electricity because it has delocalized electrons between its layers.
• Some covalent compounds can ionize in water and conduct electricity (e.g., acids like HCl produce ions).

But overall, most covalent substances are poor conductors due to their bonding nature.

4. How Bonding Determines Charge Carriers

Conductivity requires charged particles that can move:

• Metals: mobile electrons
• Ionic melts or solutions: mobile ions
• Covalent compounds: usually no mobile charges

Bonding determines:

• Whether electrons are free or fixed
• Whether ions can move or are locked in place
• Whether delocalization exists, increasing conductivity
• How easily charge carriers respond to an electric field

Thus, the internal bonding framework directly determines conductivity.

5. Influence of Physical State

Bonding explains why the physical state affects conductivity:

• Metals conduct in solid or liquid state because electrons remain mobile.
• Ionic compounds conduct only in molten or dissolved form because ions must be free.
• Covalent compounds typically never conduct unless they form ions in solution.

This shows that conductivity is not only about composition but also about how bonding organizes particles.

Conclusion

Bonding explains conductivity by determining whether charged particles such as electrons or ions are free to move. Metallic bonding provides free electrons, making metals excellent conductors. Ionic compounds conduct only when ions are free in molten or aqueous form, while covalent compounds usually lack mobile charges and therefore do not conduct electricity. By examining bonding, we can clearly understand the differences in electrical behavior among substances.