Band Theory Breakdown Conduction in Various Substances

The video explains the differences in electrical conductivity among metals, insulators, and semiconductors. Metals like sodium have no energy gap between the valence and conduction bands, allowing easy electron flow and high conductivity. Insulators have a large energy gap, preventing electron movement and resulting in no conductivity. Semiconductors have a small energy gap, allowing some electron movement at low temperatures and increased conductivity at higher temperatures. Examples include silicon and germanium for semiconductors, and diamond for insulators.

Why do metals like sodium exhibit high electrical conductivity?

• They have a small energy gap between bands.

• They have no energy gap between valence and conduction bands.

• They have a moderate energy gap between bands.

• They have a large energy gap between bands.

What is the primary reason insulators do not conduct electricity?

• They have a large energy gap between valence and conduction bands.

• They have a moderate energy gap between bands.

• They have no valence electrons.

• They have a small energy gap between bands.

What is the term used to describe the large energy gap in insulators?

• Valence gap

• Forbidden gap

• Conduction gap

• Permitted gap

How does the energy gap in semiconductors affect their conductivity at different temperatures?

• Conductivity is unaffected by the energy gap.

• Conductivity decreases with temperature.

• Conductivity remains constant regardless of temperature.

• Conductivity increases with higher temperatures.

Which of the following is an example of a semiconductor?

• Diamond

• Sodium

• Copper

• Silicon