Question

The main substance that acts as an insulator in this method of transmission of electricity is air, which is mostly
nitrogen.
The power lines are supported by solid insulators. Most solid insulators are manufactured using silica. Explain, in terms of bonding and structure, why nitrogen is a gas at room temperature but silica is a solid with a
high melting point.

Answer 1

Answer:

Nitrogen exists as a diatomic molecule, N2 (subscript 2). It exists as a gas at room temperature because of the type of interactions with other identical molecules: weak intermolecular forces are present between the molecules, specifically temporary dipole-dipole interactions.

These interactions are the second weakest type of intermolecular force (Van Der Waals and Hydrogen Bonds are the other two with Hydrogen Bonds being stronger).

Now the reason why Nitrogen exists as a gas is because these weak intermolecular forces can be overcome with little energy. Therefore, at room temperature, Nitrogen exists as a gas.

Now if we wanted to get liquid Nitrogen (quite common in Science demonstrations) we would have to cool Nitrogen down to -195.8°C (77.35°K). The energy of the particles would decrease so much that the dipole-dipole interactions would be strong enough to hold the molecules of Nitrogen together in a liquid state.