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(a) Find the energy in electron volts re...

(a) Find the energy in electron volts required to strip a calcium atom `(Z=20)` of its last electron, assuming the other 19 have been removed. How does this compare with the energy required to excite the `K_(alpha)` x-ray lines of Ca, which is about 3.7 keV? (b) Why there is a difference?

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(a) 5.4 keV, (b) because other electrons change the potential
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Calculate the wavelength and wave number of the spectrum, line when an electron of H atom falls from a higher energy state n = 3 in a state n = 2 also determine the energy of a photonm to ionic this atom by removing the electron from the second orbit .Compare it with the energy of photon required to ionic the atom by removing the electron from the ground state

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In 1931, Pauling defined the electronegativity of an atom as the tendency of the atom to attract electrons to itself when combined in a compound. The implication is that when a covalent bond is formed, the electrons used for bonding need not be shared equally by both atoms. If the bonding electrons spend more time around one atom, that atom will have a del- charge, and consequently the other atom will have a del+ charge. In the extreme case, where the bonding electrons are round one atom all of the time, the bond is ionic. Pauling and others have attempted to relate the electronegativity difference between two atoms to the amount of ionic character in the bond between them. Mulliken In 1934, Mulliken suggested an alternative approach to electronegativity based on the ionization energy and electron affinity of an atom. Consider two atoms A and B. If an electron is transferred from A to B, forming ions A^(+) and B^(-) , then the energy change is the ionization energy of atom A(I_(A)) minus the electron affinity of atom B(E_(B)) , that is I_(A)-E_(B) . Alternatively, if the electron was transferred the other way to give B^(+) and A^(-) ions, then the energy changed would be I_(B) - I_(A) . If A^(+) and B^(-) are actually formed, then this process require less energy , and (I_(A) - E_(B)) lt (I_(B) - E_(A)) Rerranging (I_(A)+E_(A)) lt (I_(A)-E_(B)) Now with respect to electronegativity for the same change, E.N_(A) lt E.N_(B) . Thus Mulliken suggested that electronegativity is proportional to I.E + E.A and could be regarded as the average of the ionization energy and the electron affinity of an atom. Electronegativity =((I+E))/(2) Mulliken used I and E values measured in electron volts, and the values were about 2.8 times alrger than the Pauling values. It is to be noted that I.E . and E.A values are defined for singular gaseous atoms. We have X atoms of A. if all the atoms gain one electron each the energy released is aeV . If Y atoms of A lose one electron each, then the energy absorbed is beV. Then the electronegativity of A on the Mulliken scale will be:

A metal plate is placed 5m from a monchromatic ligth soure whose power output is 10^(-3) W. Consider that a given ejected photoelectron may collect its energy from a circular area of the plate as large as ten atomic diameters (10^(-9m) in radius. The energy required to remove an electron through the metal surface is about 5.0 eV. Assuming light to be a wave, how long would it take for such a 'target' to soak up this much energy from such a light source.

One of the fundamental laws of physics is that matter is most stable with the lowest possible energy. Thus, the electron in a hydrogen atom usually moves in the n=1 orbit, the orbit in which it has the lowest energy. When the electon is in this lowest energy orbit, the atom is said to be in its ground electronic state. If the atom receives energy from an outside source, it is possible for the electron to move ot an orbit with a higher n value, in which case the atoms is in an excited state with a higher energy. The law of conservation of energy says that we cannot create or destroy energy. Thus, if a certain amount of external energy is required to excite an electron from one energy level to another, then that same amount of energy will be liberated when the electron returns to its initial state. Lyman series is observed when the electron returns to the lowest orbit while Balmer series is formed when the electron returns returns to second orbit. Similarly, Paschen, Brackett and Pfund series are formed when electrons returns to the third, fourth and fifth orbits from higher energy orbits respectively. When electrons return form n_(2) " to " n_(1) state, the number of lines in the spectrum will equal to ((n_(2)-n_(1))(n_(2)-n_(1)+1))/(2) If the electon comes back from energy level having energy E_(2) to energy level having energy E_(1) , then the difference may be expressed in terms of energy of photon as : E_(2)-E_(1)=DeltaE, deltaE implies (hc)/(lambda) Since, h and c are constant, deltaE corresponds to definite energy. Thus, each transition from one energy level to another will produce a radiatiob of definite wavelength. This is actually Wave number of a spectral line is given by the formula barv=R((1)/(n_(1)^(2))-(1)/(n_(2)^(2))) . where R is a Rydberg's constant (R=1.1xx10^(7) m^(-1)) An electron in H-atom in M-shell on de-excitation to ground state gives maximum ........... spectrum lines.

One of the fundamental laws of physics is that matter is most stable with the lowest possible energy. Thus, the electron in a hydrogen atom usually moves in the n=1 orbit, the orbit in which it has the lowest energy. When the electon is in this lowest energy orbit, the atom is said to be in its ground electronic state. If the atom receives energy from an outside source, it is possible for the electron to move ot an orbit with a higher n value, in which case the atoms is in an excited state with a higher energy. The law of conservation of energy says that we cannot create or destroy energy. Thus, if a certain amount of external energy is required to excite an electron from one energy level to another, then that same amount of energy will be liberated when the electron returns to its initial state. Lyman series is observed when the electron returns to the lowest orbit while Balmer series is formed when the electron returns returns to second orbit. Similarly, Paschen, Brackett and Pfund series are formed when electrons returns to the third, fourth and fifth orbits from higher energy orbits respectively. When electrons return form n_(2) " to " n_(1) state, the number of lines in the spectrum will equal to ((n_(2)-n_(1))(n_(2)-n_(1)+1))/(2) If the electon comes back from energy level having energy E_(2) to energy level having energy E_(1) , then the difference may be expressed in terms of energy of photon as : E_(2)-E_(1)=DeltaE, deltaE implies (hc)/(lambda) Since, h and c are constant, deltaE corresponds to definite energy. Thus, each transition from one energy level to another will produce a radiatiob of definite wavelength. This is actually Wave number of a spectral line is given by the formula barv=R((1)/(n_(1)^(2))-(1)/(n_(2)^(2))) . where R is a Rydberg's constant (R=1.1xx10^(7) m^(-1)) The emission spectra is observed by the consequence of transition of electrons from higher energy state to ground state of He^(+) ion. Six different photons are observed during the emission spectra, then what will be the minimum wavelength during the transition?

In 1931, Pauling defined the electronegativity of an atom as the tendency of the atom to attract electrons to itself when combined in a compound. The implication is that when a covalent bond is formed, the electrons used for bonding need not be shared equally by both atoms. If the bonding electrons spend more time around one atom, that atom will have a del- charge, and consequently the other atom will have a del+ charge. In the extreme case, where the bonding electrons are round one atom all of the time, the bond is ionic. Pauling and others have attempted to relate the electronegativity difference between two atoms to the amount of ionic character in the bond between them. Mulliken In 1934, Mulliken suggested an alternative approach to electronegativity based on the ionization energy and electron affinity of an atom. Consider two atoms A and B. If an electron is transferred from A to B, forming ions A^(+) and B^(-) , then the energy change is the ionization energy of atom A(I_(A)) minus the electron affinity of atom B(E_(B)) , that is I_(A)-E_(B) . Alternatively, if the electron was transferred the other way to give B^(+) and A^(-) ions, then the energy changed would be I_(B) - I_(A) . If A^(+) and B^(-) are actually formed, then this process require less energy , and (I_(A) - E_(B)) lt (I_(B) - E_(A)) Rerranging (I_(A)+E_(A)) lt (I_(A)-E_(B)) Now with respect to electronegativity for the same change, E.N_(A) lt E.N_(B) . Thus Mulliken suggested that electronegativity is proportional to I.E + E.A and could be regarded as the average of the ionization energy and the electron affinity of an atom. Electronegativity =((I+E))/(2) Mulliken used I and E values measured in electron volts, and the values were about 2.8 times alrger than the Pauling values. It is to be noted that I.E . and E.A values are defined for singular gaseous atoms. For a reaction A(g)+B(g) rar AB(S) the enthalpy change for the recation will be [assuming AB(s) to be an ionic compound] If I.E_(A)+E.A_(A) lt I.E_(B) +E.A_(B)

One of the fundamental laws of physics is that matter is most stable with the lowest possible energy. Thus, the electron in a hydrogen atom usually moves in the n=1 orbit, the orbit in which it has the lowest energy. When the electon is in this lowest energy orbit, the atom is said to be in its ground electronic state. If the atom receives energy from an outside source, it is possible for the electron to move ot an orbit with a higher n value, in which case the atoms is in an excited state with a higher energy. The law of conservation of energy says that we cannot create or destroy energy. Thus, if a certain amount of external energy is required to excite an electron from one energy level to another, then that same amount of energy will be liberated when the electron returns to its initial state. Lyman series is observed when the electron returns to the lowest orbit while Balmer series is formed when the electron returns returns to second orbit. Similarly, Paschen, Brackett and Pfund series are formed when electrons returns to the third, fourth and fifth orbits from higher energy orbits respectively. When electrons return form n_(2) " to " n_(1) state, the number of lines in the spectrum will equal to ((n_(2)-n_(1))(n_(2)-n_(1)+1))/(2) If the electon comes back from energy level having energy E_(2) to energy level having energy E_(1) , then the difference may be expressed in terms of energy of photon as : E_(2)-E_(1)=DeltaE, deltaE implies (hc)/(lambda) Since, h and c are constant, deltaE corresponds to definite energy. Thus, each transition from one energy level to another will produce a radiatiob of definite wavelength. This is actually Wave number of a spectral line is given by the formula barv=R((1)/(n_(1)^(2))-(1)/(n_(2)^(2))) . where R is a Rydberg's constant (R=1.1xx10^(7) m^(-1)) What transition in the hydrogen spectrum would have the same wavelength as Balmer transitio, n=4 " to "n=2 in the He^(+) spectrum?

RESNICK AND HALLIDAY-ALL ABOUT ATOMS -PROBLEMS
  1. The wavelength of the K(alpha) line from iron is 193 pm. What is the e...

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  2. An electron in a multielectron atom has m(f)=+4. For this electron, wh...

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  3. A hypothetical atom has energy levels uniformly separated by 1.2 eV. A...

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  4. Ruby lases at a wavelength of 694 nm. A certain ruby crystal has 4.00x...

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  5. How many electron states are there in a shell defined by the quantum n...

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  6. Through what minimum potential difference must an electron in an x-ray...

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  7. Calculate the ratio of the wavelength of the K(alpha) line for niobium...

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  8. An electron is in a state with l=3, (a) What multiple of h gives the m...

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  9. When electrons bombard a molybdenum target, they produce both continuo...

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  10. An electron in a hydrogen atom is in a state with l=5. What is the min...

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  11. An electron is in a state with n=4. What are (a) the number of possibl...

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  12. (a) How many l values are associated with n=3? (b) How many m(l), valu...

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  13. The active medium in a particular laser that generates laser light at ...

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  14. How many electron states are in these subshells: (a) n=4,l=3, (b) n=3,...

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  15. (a) What is the magnitude of the orbital angular momentum in a state w...

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  16. Fig shows that energy levels of a mercury atom. Electrons with kinetic...

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  17. The kalpha X-rays of aluminium (Z = 13 ) and zinc ( Z = 30) have wavel...

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  18. An imaginaryy atom whose energy levels are shown here undergoes an Aug...

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  19. (a) Find the energy in electron volts required to strip a calcium atom...

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  20. The Ka X-ray of molybdenum has wavelength 71 pm. If the energy of a mo...

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