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1) Nanotechnology: The branch of technology that deals with study and application of small things of size less than 100 nanometres, especially the manipulation of individual atoms and molecules.
Nanomaterial: A material having particles or constituents of nanoscale dimensions, or one that is produced by nanotechnology.
2) Atom: The smallest particle of a chemical element that can exist.
Molecule: A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Ion: An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Bond: A bond is a lasting attraction between atoms that enables the formation of chemicalcompounds.
Strong bond: The attaraction between atoms is strong it forms strongest bond. Ex: Ionic bond.
Weak bond: The attaraction between atoms is weak it forms weakest bond. Ex: Vanderwall bond.
4) Conduction Band: A delocalized band of energy levels in a crystalline solid which is partly filled with electrons. These electrons have great mobility and are responsible for electrical conductivity.
Valance band: The valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature, while the conduction band is the lowest range of vacant electronic states.
Bnad Gap: The band gap generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors.
The necessary energy for diamond is greater than 5.5 eV, Si is >1.1 eV and Ge is > 0.6 eV. The wavelength is calculated by using formula E=hc/lambda, then corresponding wavelength lambda=1239 nm.eV/E(eV).
So for Diamond wavelength=225 nm, Si =1126 nm and Ge=2065 nm.
The band gap energy of semiconductors tends to decrease with increasing temperature. When temperature increases, the amplitude of atomic vibrations increase, leading to larger interatomic spacing. The interaction between the lattice phonons and the free electrons and holes will also affect the band gap a little. The relationship between band gap energy and temperature can be described by Varshni's empirical expression,
where Eg(0), ? and ? are material constants.
What is nanotechnology? What is nanomaterial? What is atom, molecule, ion, and bond? Describe strong and...
Theory section is below for the equations PRELAB Read the theory section below. Calculate the photon wavelength in nm corresponding to a photon energy equal to the theoretical band gap energy of S1.121 eV and GaAs, 1.422 eV. These will be used to set the monochromator. THEORY One of the most important characteristics of a semiconductor is its band gap energy Eg Whereas an electron in an isolated atom has discrete energy levels, an electron in a semiconductor crystal has...
Explain the answer please. ) 1 on electronegativity differences, which of the following is most likely to be ionie? BaF2 b) Bra c) PH d) NO e CL 6. How many electrons can be contained in all of the orbitals with n-4? c) 10 d) 18 32 Which of the following molecules has no dipole moment? mause it is a Hencar wno 7. NH c) H20 d) all e) none 8. How many electrons can be described by the quantum...
Read the case study and answer the following questions 1. Describe Amy's entrepreneurial style. What are the strengths and weaknesses of Amy's style? How does her style impact an expansion decision? 2. Identify Amy's mission and key goals and objectives for the company 3. What internal strengths and weaknesses exist? What are the external opportunities and threats facing Amy's Bread? 4. Who are Amy's customers? Should Amy concentrate on just retail or wholesale business? 5. What would you do if...