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A photon of wavelength 4 × 10–7 m strikes on the metal surface, the work function of the metal being 2.13 eV. Calculate
- the energy of the photon (eV),
- the kinetic energy of the emission, and
- the velocity of the photoelectron (1 eV = 1.6020 × 10–19 J).
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A 25-watt bulb emits monochromatic yellow light of the wavelength of 0.57μm. Calculate the rate of emission of quanta per second.
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Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency (v0) and work function (W0) of the metal.
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Following results are observed when sodium metal is irradiated with different wavelengths. Calculate (a) threshold wavelength and, (b) Planck’s constant.
| λ (nm) | 500 | 450 | 400 |
| v × 10-5 (cm s-1) | 2.55 | 4.35 | 5.35 |
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The electron energy in the hydrogen atom is given by En = (–2.18 × 10–18)/n2 J. Calculate the energy required to remove an electron completely from the n = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?
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An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the atomic symbol.
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An ion with mass number 37 possesses one unit of negative charge. If the ion contains 11.1% more neutrons than the electrons, find the symbol of the ion.
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An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.
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In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of 3.15 × 10–18 J from the radiations of 600 nm, calculate the number of photons received by the detector.
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The work function for caesium atom is 1.9 eV. Calculate
- the threshold wavelength and
- the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength 500 nm, calculate the kinetic energy and the velocity of the ejected photoelectron.
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The ejection of the photoelectron from the silver metal in the photoelectric effect experiment can be stopped by applying the voltage of 0.35 V when the radiation 256.7 nm is used. Calculate the work function for silver metal.
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Explain the formation of H2 molecule on the basis of valence bond theory.
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What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm3 flask at 27 °C ?
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A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
C6H5OH
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
C6H5NO2
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
CH3CH = CHCHO
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
C6H5 – CHO
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
\[\ce{C6H5 - \overset{+}{C}H2}\]
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Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.
\[\ce{CH3CH = CH\overset{+}{C}H2}\]
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