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Recent questions tagged unit2
Questions
Energy required to stop the ejection of electrons from $Cu$ plate is 0.24eV.Calculate the work function when radiations of $\lambda=253.7nm$ strikes the plate.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q121
difficult
asked
Jan 17, 2014
by
sreemathi.v
1
answer
An electron has a total energy of 2MeV.Calculate the effective mass of the electron in Kg and its speed .Assume rest mass of electron 0.511MeV
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q120
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Two hydrogen atoms collide head on and end up with zero kinetic energy.Each atom then emits a photon of wavelength 121.6nm.Which transition leads to this wavelength ?How fast were the hydrogen atoms traveling before collision?$R_H=1.097\times 10^7m^{-1}$ and $m_H=1.67\times 10^{-27}Kg$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q119
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
With what velocity must an electron travel so that its momentum is equal to that of a photon of wavelength $\lambda=5200A^{\large\circ}$?
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q118
medium
cbse
ch2
structure-of-atom
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate momentum of radiations of wavelength 0.33nm
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
quantum-mechanical-model
q117
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate the angular frequency of an electron occupying the second Bohr's orbit of $He^+$ ion.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q116
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Find the quantum no 'n' corresponding to the excited state of $He^+$ ion if on transition to the ground state that ion emits two photons in succession with wavelength 108.5 and 30.4nm
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q115
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate the wavelength emitted during the transition of electron in between two levels of $Li^{+2}$ ion whose sum is 4 and difference is 2.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q114
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
A stationary $He^+$ ion emitted a photon corresponding to the first line $(H_{\alpha})$ of the Lyman series .That photon liberated a photo electron from a stationary H atom in ground state.What is the velocity of photo electron?$R_H=109678cm^{-1}$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q113
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
The angular momentum of an electron in a Bohr's orbit of H-atom is $4.2178\times 10^{-34}Kg-m^2/s$.Calculate the spectral line emitted when electron falls from this level to next lower level.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q112
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate the uncertainty in velocity of a cricket ball (mass=0.15Kg) if its uncertainty position is of the order of $1A^{\large\circ}$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q111
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
The vapours of Hg absorb some electrons accelerate by a potential difference of 4.5volts as a result of which light is emitted .If the full energy of single incident electron is supposed to be converted into light emitted by single Hg atom,find the wave number $\big(\large\frac{1}{\lambda}\big)$ of the light.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q110
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
An electron beam can undergo diffraction by crystals.Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to $1.54A^{\large\circ}$?
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q109
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Energy of the electron in H-atom is 1.50 times as much as energy as the minimum required for its escape (13.6eV) from the atom.Calculate the wavelength of the emitted electron.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q108
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
When a certain metal was irradiated with light of frequency $1.6\times 10^{16}Hz$,the photoelectrons emitted had twice the kinetic energy as did photoelectrons emitted when the same metal was irradiated with light of frequency $1.0\times 10^{16}$Hz.Calculate $V_0$(threshold frequency) for the metal.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q107
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
What electron transition in a hydrogen atom,starting from the orbit $n=7$ will produce infrared light of wavelength 2170nm?( $R_H=1.09677\times 10^7m^{-1})$
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
bhor's-model
q106
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
If uncertainties in the measurement of position and momentum are equal,calculate uncertainty in the measurement of velocity.
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
quantum-mechanical-model
q105
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
One quantum is absorbed per molecule of gaseous iodine for converting into iodine atoms.If light absorbed has wavelength of $5000A^{\large\circ}$,calculate energy required in KJ/mol.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q104
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Three isotopes of an element have mass numbers m,m+1 and m+2.If the mean mass number is ( m +0.5) then which of the following ratios may be accepted for m,(m+1) and (m+2) in that order
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
atomic-models-(rutherford-and-thomson)
q103
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate the uncertainty in velocity of an electron if uncertainty in its position is of the order of $1A^{\large\circ}$
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
quantum-mechanical-model
q102
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
An electron moves in an electric field with a kinetic energy of 2.5eV.What is the associated De-Broglie wavelength?
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q101
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate the accelerating potential that must be imparted to a proton beam to give it an effective wavelength of 0.005nm.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q100
difficult
asked
Jan 16, 2014
by
sreemathi.v
1
answer
The energy E for an electron in H atom is $\large\frac{21.7\times 10^{-12}}{h^2}$erg.Calculate the energy required to remove electron completely from $n=2$ orbit.Also calculate the longest wavelength of light that can be used to cause this transition.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q99
medium
asked
Jan 16, 2014
by
sreemathi.v
1
answer
Calculate $\lambda$ of the radiations when the electrons jumps from III to II orbit for H atom.The electronic energy in II and III Bohr's orbit of H atom are $-5.42\times 10^{-12}$ and $-2.41\times 10^{-12}$erg respectively.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q98
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the momentum of electron moving with $\large\frac{1}{3}$rd velocity of light
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
quantum-mechanical-model
q97
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the wavelength of moving electron having $4.55\times 10^{-25}$Joule of kinetic energy
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
bhor's-model
q96
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Find out the number of waves made by a Bohr electron in one complete revolution in its third orbit
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q95
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n=4 to n=2 of $He^+$ spectrum ?
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
bhor's-model
q94
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Estimate the difference in energy between first and second Bohr's orbit for a H atom.At what minimum atomic no a transition from $n=2$ to $n=1$ energy level would result in the emission of $X$-rays with $\lambda=3\times 10^8m$ ?which hydrogen atom like species does this atomic no corresponds to ?
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q93
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the energy emitted when electrons of 1.0g atom of hydrogen under go transition giving the spectral lines of lowest energy in the visible region of its atomic spectra.$R_H=1.1\times 10^7m^{-1},c=3\times 10^8msec^{-1}$ and $h=6.62\times 10^{-34}Jsec$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q92
difficult
asked
Jan 15, 2014
by
sreemathi.v
2
answers
Calculate the wavelength of radiations emitted producing a line in Lyman series,when an electron falls from fourth stationary state in hydrogen atom $(R_H=1.1\times 10^7m^{-1})$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q91
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the frequency of the spectral line emitted when the electron in n=3 in H-atom de-excites to ground state.$(R_H=109737/cm)$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q90
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Electromagnetic radiations of wavelength 242nm is just sufficient to ionize sodium atom.Calculate the ionization energy of sodium in KJ/mol.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q89
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The ionization energy of $He^+$ is $19.6\times 10^{-18}J/atom$.Calculate the energy of first stationary state of $Li^{2+}$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q88
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The ionization energy of H atom is $13.6eV$.What will be ionization energy of $He^+$ and $Li^{2+}$ ions?
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
quantum-mechanical-model
q87
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the velocity of an electron placed in $III$ orbit of H atom.Also calculate the no of revolution /sec round the nucleus.
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q86
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Calculate the energy required to excite one litre of hydrogen gas at 1atm and 298K to the first excited state of atomic hydrogen.The energy for the dissociation of H-H bond is $463KJmol^{-1}$
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q85
difficult
asked
Jan 15, 2014
by
sreemathi.v
1
answer
A bulb emits light of $\lambda=4500A^{\circ}$ .The bulb is rated as 150watt and 8% of the energy is emitted as light.How many photons are emitted by the bulb per second?
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q84
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Iodine molecule dissociates into atoms after absorbing light of 4500$A^{\circ}$ .If one quantum of radiation is absorbed by each molecule,calculate the kinetic energy of iodine atoms (Bond energy of $I_2=240KJmol^{-1}$)
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q83
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The number of radial nodes of 3s and 2p orbitals are respectively
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q82
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom
sat
chemistry
atomic-structure
jeemain
physical-chemistry
class11
unit2
bhor's-model
q81
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The quantum numbers $\large\frac{1}{2}$ and $-\large\frac{1}{2}$ for the electron spin represents :
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q80
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
If the nitrogen atom had electronic configuration $1s^7$,it would have energy lower than that of normal ground state configuration $1s^22s^22p^3$,because the electrons would be closer to the nucleus.Yet $1s^7$ is not observed because it violates
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q79
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
Number of nodal plane in px-orbital is
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q78
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The wavelength of a golf ball weighing 200g and moving with a speed of 5m/h is of the order :
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q77
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The electronic configuration of an element is $1s^2,2s^22p^6,3s^23p^63d^5,4s^1$.This represents its
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q76
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The electrons,identified by quantum number n and l,(i) n=4,l=1;(ii) n=4,l=0;(iii) n=3,l=2;(iv) n=3,l=1 can be placed into order of increasing energy,from the lowest to highest,as :
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q75
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The energy of an electron in the first orbit of H-atom is -13.6eV.The possible value of excited state for electron in bohr orbit of H atom are :
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q74
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
The first use of quantum theory to explain the structure of atom was given by
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
bhor's-model
q73
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
For a d electron,the orbital angular momentum is :
jeemain
chemistry
physical-chemistry
class11
unit2
atomic-structure
quantum-mechanical-model
q72
medium
asked
Jan 15, 2014
by
sreemathi.v
1
answer
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