Valence Band and Conduction Band in Atoms Quiz
30 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the role of free electrons in a conductor?

  • They create a forbidden energy gap
  • They are responsible for the conduction of current (correct)
  • They fill the valence band
  • They are responsible for the bonding of atoms
  • Which type of material has a full valence band?

  • Inert gases (correct)
  • Metals
  • Semiconductors
  • Insulators
  • What happens if a substance has an empty conduction band?

  • It becomes an insulator
  • It can conduct current effectively
  • It cannot conduct current (correct)
  • It becomes a semiconductor
  • What does the forbidden energy gap represent?

    <p>The separation between conductance band and valence band</p> Signup and view all the answers

    What defines whether the valence band is full or partially filled?

    <p>The type of substance</p> Signup and view all the answers

    What is the significance of the conduction band being empty in insulators?

    <p>Insulators have low conductivity</p> Signup and view all the answers

    Which orbit has more energy, the inner or outer orbit?

    <p>Outer orbit</p> Signup and view all the answers

    What form does an electron emit when it jumps from a higher orbit to a lower one?

    <p>Electromagnetic radiations</p> Signup and view all the answers

    What is a convenient way to represent the energy of different orbits?

    <p>Energy level diagram</p> Signup and view all the answers

    In a solid atom influenced by neighboring atoms, do electrons in any orbit have a single energy value?

    <p>No, they have a range of energies</p> Signup and view all the answers

    What happens to the energy level as the orbit of an electron becomes larger?

    <p>The energy level increases</p> Signup and view all the answers

    How are the values of radii for orbits determined?

    <p><strong>By quantum considerations</strong></p> Signup and view all the answers

    Electrons in the third orbit of an atom have _______ energy compared to the electrons in the second orbit.

    <p>more</p> Signup and view all the answers

    When an electron jumps from a higher orbit to a lower orbit, it _______ energy.

    <p>emits</p> Signup and view all the answers

    According to Bohr’s theory of atom, which of the following is quantized?

    <p>angular momentum of electron</p> Signup and view all the answers

    A semiconductor has an almost empty _______ band.

    <p>conduction</p> Signup and view all the answers

    The electrons in the conduction band are known as _______.

    <p>free electrons</p> Signup and view all the answers

    In insulators, the energy gap between valence and conduction bands is _______.

    <p>very large</p> Signup and view all the answers

    According to Bohr, what happens when an electron is given additional energy?

    <p>It is lifted to a higher orbit</p> Signup and view all the answers

    What is the relationship between the radius of an electron orbit and its energy according to Bohr?

    <p>The larger the orbit radius, the greater is the energy</p> Signup and view all the answers

    Why does an atom in an excited state not last long?

    <p>Because electrons quickly fall back to lower orbits</p> Signup and view all the answers

    What happens when an electron falls back to its original lower orbit?

    <p>It releases acquired energy as heat, light, or radiation</p> Signup and view all the answers

    How many electrons does a silicon atom have according to Bohr's model?

    <p>14</p> Signup and view all the answers

    What happens if an electron in the first orbit is lifted to the second orbit?

    <p>The right amount of energy should be supplied</p> Signup and view all the answers

    What happens to the resistance of an insulator as the temperature increases?

    <p>Decreases</p> Signup and view all the answers

    Why do conductors like copper and aluminium easily allow the passage of electric current?

    <p>Due to the overlapping of valence and conduction bands</p> Signup and view all the answers

    How can the electrical behavior of conductors be satisfactorily explained?

    <p>By the band energy theory of materials</p> Signup and view all the answers

    What distinguishes semiconductors from conductors and insulators in terms of energy bands?

    <p>Valence band is almost empty, conduction band is almost full</p> Signup and view all the answers

    Why is a smaller electric field required in semiconductors compared to insulators to push electrons from the valence band to the conduction band?

    <p>Because semiconductors have a small energy gap between bands</p> Signup and view all the answers

    What characteristic lies inbetween conductors and insulators that defines semiconductors?

    <p>Overlapping energy bands</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Browser