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Zorluk: ZorConductors, Insulators, and Semiconductors

An electrical technician is evaluating four substances for an electronics assembly based on how easily charge carriers move through their atomic lattices. What is the correct order of these materials when arranged from highest electrical conductivity (greatest electron flow) to lowest electrical conductivity (highest resistance to current flow) at room temperature (25∘C25^\circ\text{C})?

  1. 1Silver
  2. 2Intrinsic Germanium
  3. 3Intrinsic Silicon
  4. 4Mica

Cevap

Silver, followed by Intrinsic Germanium, Intrinsic Silicon, and finally Mica.
Electrical conductivity is determined by the density of free charge carriers available in a material's conduction band. Silver is an excellent metallic conductor with free electrons that readily drift under an applied electric field. Germanium and silicon are Group IV semiconductors; because germanium has a narrower forbidden bandgap (0.67 eV0.67\text{ eV}) than silicon (1.12 eV1.12\text{ eV}), more electron-hole pairs are thermally excited across the gap at room temperature, making germanium more conductive than silicon. Mica is an inorganic insulator with tightly held valence electrons and a very wide forbidden energy gap, giving it the lowest electrical conductivity in the sequence.

Adım Adım Çözüm

1
Identify the metallic conductor
Silver is identified as the conductor with the highest concentration of free valence electrons.
Metals have overlapping valence and conduction bands, providing high electrical conductivity.
2
Compare the semiconductor bandgaps
Intrinsic Germanium (Eg≈0.67 eVE_g \approx 0.67\text{ eV}) has higher conductivity than Intrinsic Silicon (Eg≈1.12 eVE_g \approx 1.12\text{ eV}).
A smaller bandgap allows more valence electrons to bridge into the conduction band at room temperature.
3
Identify the electrical insulator
Mica is placed last with the lowest electrical conductivity.
Insulators have full valence bands separated from conduction bands by large forbidden energy gaps.

Anahtar Kavram

Ranking material electrical conductivity based on atomic structure, valence electron availability, and energy bandgap size across conductors, semiconductors, and insulators.
Tahmini Süre:1m 30s
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Conductors, Insulators, and Semiconductors

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