Circle the best answer to the following questions From the B

Circle the best answer to the following questions. From the Bohr model we learn: The origin of line spectra for glowing hydrogen gas. Those energies for electrons in a hydrogen atom are quantized. The electron orbits have quantized radii All of the above. Silicon is: A rare element in the earth\'s surface A Group V element with five valence electrons. Both A & B. None of the above. The work function of a metal is: The same for different metals. An energy barrier that keeps conduction electrons inside a metal. Has the units of meters. All of the above. In a fictional atom called Hockeygen, the n=3 energy state has an energy of -2.0 eV, and the n=1 energy state has an energy of -5 eV. An electron makes a transition from the n=3 to the n=1 energy state of this atom. We expect: The photon absorbed has an energy of 3 eV. The photon emitted has an energy of 3 eV. The photon emitted has an energy of 5 eV, The photon absorbed has an energy of 5 eV. A typical silicon atom inside a single crystal of silicon has: 4 nearest neighbor dopant atoms. 8 nearest neighbor silicon atoms. 4 nearest neighbor silicon atoms. 4 electrons and 4 holes. For commercial single crystal silicon, typical dopant densities are: 10^15 - 10^17 dopants/cm^3. 10^5-10^7 dopants/cm^3 5 times 10^22 dopants/cm^3 6.02 times 10^23 dopants/cm^3 The type of solid that has the highest degree of atomic order is: Single crystal. Polycrystalline. Amorphous. Metals.

Solution

Problem 1 a :The model\'s key success lay in explaining the Rydberg formula for the spectral emission lines of atomic hydrogen. While the Rydberg formula had been known experimentally, it did not gain a theoretical underpinning until the Bohr model was introduced. Not only did the Bohr model explain the reason for the structure of the Rydberg formula, it also provided a justification for its empirical results in terms of fundamental physical constants. Answer: 1

Problem 1 b : Measured by mass, silicon makes up 27.7% of the Earth\'s crust and is the second most abundant element in the crust, with only oxygen having a greater abundance.Silicon is usually found in the form of complex silicate minerals, and less often assilicon dioxide (silica, a major component of common sand).

It belongs to the 14th group of periodic table. Answer 4

Problem 1 c : the minimum quantity of energy which is required to remove an electron to infinity from the surface of a given solid, usually a metal. Answer 2

Problem 1 d: ENERGY required to make transition is equal to E1-E3 = -5-(-2) = -3eV

So a photon with energy = 3eV is released in transition. Answer 2

Problem 1 e: For single-crystal silicon, each silicon atom has four nearest neighbors. Since Si is a column IV element and has four valence electrons, each of these electrons is shared with one of its four nearest neighbor Si atoms. Answer 3

Problem 1 f: In intrinsic crystalline silicon, there are approximately 5×10²² atoms/cm³. Doping concentration for silicon semiconductors may range anywhere from 10¹³ cm³ to10¹⁸ cm³. Doping concentration above about 10¹⁸ cm³ is considered degenerate at room temperature. Answer 1

Problem 1 g: All solids, both crystalline and amorphous, exhibit short-range (atomic-scale) order. (Thus, the term amorphous, literally “without form or structure,” is actually a misnomer in the context of the standard expression amorphous solid.) The well-defined short-range order is a consequence of the chemical bonding between atoms, which is responsible for holding the solid together. Answer 2