Atomic mass of `._(3)^(7)Li` is 7.01600u and that of `._(4)^(7)Be` is 7.01693u. Mass of one electron in atomic mass unit is 0.00055 u. if it is observed that `._(4)^(7)Be` decays into `._(3)^(7)Li`, what kind of decay will it be?
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Explain the following: (i) Why argon (atomic mass `= 39.94)` has been placed before potassium (atomic mass `= 39.10)` in the Modern periodic table? (i
Correct Answer - (i) In modern periodic table, elements have been placed in order of their increasing atomic numbers. The atomic number of argon is 18 and that of potassium...
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A single electron ion has nuclear chrage `+Ze` where `Z` is atomic number and `e` is electronic charge. It requires `16.52 eV` to excite the electron
Correct Answer - (a) `Z=3`, (b) `108.8 eV`, (c) `1.013xx10^(-8) m`, (d) `122.4 eV` (a) `16.52=(E_(3)-E_(2))xxZ^(2)` `16.52=1.89xxZ^(2) rArr Z^(2)=9 "or" Z=3` (b) `(E_(3)-E_(1))_(z)=12.09xxZ^(2)=12.09xx9=108.81 eV` (c ) `lambda=12400/(DeltaE_(1 tp oo))=12400/(13.6xx3^(2))=101.3 Å=1.013xx10^(-8) m`,...
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A direct current deposits deposits 54 g of silver (Atomic mass = 108) during electrolysis. How much aluminimum (Atomic mass =27) would be deposited fr
Correct Answer - A Equivalent mass of silver = 108 Equivalent mass of aluminium in `(AlCl_(3))=27/3 =9` `W_(Ag)/W_(Al)=E_(Ag)/E_(Al)` `54/W_(Al)=108/9` `W_(Al)=4.5 g`
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If the sum of atomic mass of 3 elements forming Dobereiner traid is 69, then atomic mass of second element
Correct Answer - D `{:(Li,,Na,,K),(7,+,23,+,39=69):}` `(7+39)/(2)=23`
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If in a system unit of mass is 5kg, unit of length is 10m and unit of time as 5sec, then what will be the value of 1 unit energy in new system.
`[E]=[ML^(2)T^(-2)]=(5)` `=(10)^(2)(5)^(2)=20` joules
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In an electron capture process, a nucleus captures an electron from K shell of the atom. The electron is having a binding energy of `B_(0)`. Followed
Correct Answer - `B_(0)`
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An `X-`ray tube operates at `27 kV`. Find the maximum speed of an electron striking the anticathode. Given mass of electron `=9xx10^(31)kg` and charge
Correct Answer - `9.79xx10^(7)ms^(-1)`
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The energy of K-electron in tungsten is -20.0 keV and of an L-electron is -2.0 ke V. Find the wavelength of X-rays emitted when an electron jumps from
Correct Answer - 0.6875 Å
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Find the minimum energy that a `gamma`-ray must have to give rise to an electron -positron pair. `{:("Mass of electron",= 0.00055 am u,),("Mass of pos
Correct Answer - 1.024 MeV
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Calculate the amount of energy set free by the annigilation of an electron and a positron. Given that mass of electron `= 0.00055` amu and positron =
Correct Answer - 1.0211 MeV
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