(a)
Interpretation:
The formation of band of molecular orbitals formed from individual atomic orbitals has to be shown and the reason why the material is electrical insulator has to be explained.
Concept introduction:
Molecular orbital theory:
Molecular orbital theory describes molecules in electronic structure. Electrons are moving around nuclei in entire molecule. Atomic orbitals in which electrons present in one atom. Molecular orbitals in which electrons are present in more atoms. Bonding and anti-bonding orbitals are found in molecular orbital theory.
(b)
Interpretation:
The molecular orbital energy level diagram for the doped material and the population of the band has to be drawn and shown. The reason why doped material can conduct electricity has to be explained.
Concept introduction:
Molecular orbital theory:
Molecular orbital theory describes molecules in electronic structure. Electrons are moving around nuclei in entire molecule. Atomic orbitals in which electrons present in one atom. Molecular orbitals in which electrons are present in more atoms. Bonding and anti-bonding orbitals are found in molecular orbital theory.
(c)
Interpretation:
The type of the doped material has to be described with an explanation.
Concept introduction:
Semiconductor: A material which can conduct electricity in range between a metal and an insulator is known as semiconductor. Addition of small amount of impurities increases conductivity of semiconductor and the process is known as doping. n-type and p-type are two types of doped semiconductors.
n-type: This type of doped semiconductor is the one in which many free electrons are present in conduction band.
p-type: This type of doped semiconductor is the one in which holes are present in valence band.
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General Chemistry: Atoms First
- Thallium forms the compound TlI₃. What is the apparentoxidation state of Tl in this compound? Given that the anion is I₃⁻, what is the actual oxidation state of Tl? Draw the shape ofthe anion, giving its VSEPR class and bond angles. Propose areason why the compound does not exist as (Tl³⁺)(I⁻)₃.arrow_forwardPredict the structure of each of the following silicate minerals (network, sheets, double chains, and so forth). Give the oxidation state of each atom.(a) Apophyllite, KCa4(Si8O20)F ? 8 H2O(b) Rhodonite, CaMn4(Si5O15)(c) Margarite, CaAl2(Al2Si2O10)(OH)2arrow_forwardPhosphorus (P) is present in a germanium (Ge) sample. Assume that one of its five valence electrons revolves in a Bohr orbit around each P+ ion in the Ge lattice. (a) If the effective mass of the electron is 0.17 me and the dielectric constant of Ge is 16, find the radius of the first Bohr orbit of the electron. (b) Ge has a band gap (Eg) of 0.65 eV. How does the ionization energy of the above electron comparing to Eg and kBT at room temperature?arrow_forward
- Write balanced chemical equations for the following reactions:(a) sodium oxide added to water(b) cesium carbonate added to an excess of an aqueous solution of HF(c) aluminum oxide added to an aqueous solution of HClO4(d) a solution of sodium carbonate added to solution of barium nitrate(e) titanium metal produced from the reaction of titanium tetrachloride with elemental sodiumarrow_forwardSketch the band structure of a Li AND a Si crystal. (ii) How would you expect the electrical conductivity in Li AND Si crystals to vary with temperature? (iii) Account for the fact that the conductivity of Si is enhanced by the addition of small amounts of B.arrow_forwardSelenium is prepared by the reaction of H₂SeO₃ with gaseous SO₂. (a) What redox process does the sulfur dioxide un-dergo? What is the oxidation state of sulfur in the product? (b) Given that the reaction occurs in acidic aqueous solution,what is the formula of the sulfur-containing species? (c) Write the balanced redox equation for the processarrow_forward
- Explain why SO2 is used as a reducing agent but SO3 is notarrow_forwardite form of iron has fcc crystal lattice structure,whereas its alpha form has bcc crystal lattice structure. Assuming closest packed arrangement of iron atoms, what will be the ratio of density of Austenite to that of alpha iron?arrow_forward(a) (i) (ii) (iii) With the aid of a simple schematic, explain what covalent bonding is and how it is formed. What are the differences between a covalent bond and an ionic bond? Which type of bond is found in crystalline silicon? At room temperature do you expect an ionic crystal to be a good electrical conductor or a good electrical insulator? Explain why.arrow_forward
- Account for the relative band gap energies of semiconductors interms of periodic trends?arrow_forwardExplain why LiFeO2 and Li2TiO3 (rock salt structure) form a wide range of solid solutions with MgO(rock salt structure), but not with ZnO (wurzite structure).arrow_forwardStructure of the Bis-( dimethylglyoximato) nickel(II) ( write the C.N , geometry type):arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning