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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 651. |
According to classical theory if an electron is moving in a circular orbit around the nucleus:A. it will contuinue to do so for somethingB. its orbit will continuously shrinkC. its orbit will continuously enlargeD. it will continue to do so for all the time. |
| Answer» Correct Answer - B | |
| 652. |
Spin angular momentum for unpaired electron in sodium ( Atomic No. `=11)` isA. `(sqrt(3))/(2)`B. `0.866h//2pi`C. `-(sqrt(3))/(2)(h)/(2pi)`D. None of these |
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Answer» Correct Answer - B `sqrt(s(s+1))(h)/(2pi)=sqrt((1)/(2)((1)/(2)+1))(h)/(2pi)=(sqrt(3))/(2)(h)/(2pi)=0.866(h)/(2pi)` |
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| 653. |
How much energy will be released when a sodium ion and a chloride ion, originally at infinite distance are brought together to a distance of 2.76Ã… (the shortest distance of approach in a sodium chloride crystal)? Assume that ions act as point charges, each with a magnitude of `1.6xx10^(-19)C`. Permittivity constant of the medium is `9xx10^(9)Nm^(2)C^(-2)`. |
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Answer» Energy released `=-K(q_(1)q_(2))/(r)` `=-(9xx10^(9)xx(1.6xx10^(-19))^(2))/(2.76xx10^(-10))=-8.35xx10^(-19)J`. |
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| 654. |
How much energy will be released when a sodium ion and a chloride ion, originally at infinite distance are brought together to a distance of ` 2. 76 Å` ( the shortest distance fo approach in a sodium chloride crystal ? Assume that the ions act as point charges , each with a mangitude of ` 1. 60 xx 10^(-19) C` ( the electronic charge ) Also if lattice enrgy of Nacl is ` 185 ` kcal , how the lower value obtained per mole by above calculation can be explained ? |
| Answer» Correct Answer - 119.595 kcal , | |
| 655. |
A potential difference of `20kV` is applied across an `X-ray tube. Find the minimum wavelength of X-ray generated. |
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Answer» Correct Answer - `0.62A^(@)` `2000eV=(hc)/(lambda)=(1240)/(lambda(nm))` `lambda=(1240)/(20000)=62xx10^(-3)nm=0.62Å` |
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| 656. |
The atomic number of chromium is `24` Its electronic coefigueration in ground state in `1s^(2) 2s^(2)2p^(6)3s^(2)4s^(1) 3d^(5)` .Chromium atom by using `3` electron from `Cr ^(2+)` .A chromium atom contain `17%` morte neutron than the proton. Now answer the following questions The number of electron having `n = 3` and `m_(1) = 0` in chromium atom isA. 2B. 5C. 4D. 1 |
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Answer» Correct Answer - B `2` electrons in `3s,2` electron in `3p` and `1` electron in `3d` have `m_(1) = 0` |
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| 657. |
The atomic number of chromium is `24` Its electronic coefigueration in ground state in `1s^(2) 2s^(2)2p^(6)3s^(2)4s^(1) 3d^(5)` .Chromium atom by using `3` electron from `Cr ^(2+)` .A chromium atom contain `17%` morte neutron than the proton. Now answer the following questions The number of unopaired electron in `Cr ^(2+)`ion isA. 3B. 6C. 5D. 1 |
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Answer» Correct Answer - A `Cr^(3+),1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(3)`.Three electrons in `3d` sub-shell are unpaired |
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| 658. |
Which of the following species will produce the shortest wavelength for the transition `n = 2` to `n= 1` ?A. H-atomB. D-atomC. `He^+` ionD. `Li^(2+)` ion |
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Answer» Correct Answer - D `Delta` for `Li(2+) = E_2 - E-1` is maxium as ` E_(nLi^(2+)) = E_(nh) xx Z^2`. |
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| 659. |
The number of nodals plates of zeroelectron density in the `d_(xy)` orbital isA. 1B. 2C. 3D. 4 |
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Answer» Correct Answer - B xz and yz are palnes with zero electron density for `d_(xy)` orbital |
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| 660. |
Which of the following species will produce the shortest wavelength for the transition `n = 2 "to" n= 1` ?A. Hydrogen atomB. Singly ionised heliumC. Deuterium atomD. Dioubly ionised lithium |
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Answer» Correct Answer - D Shortest `lambda` will be produced in the ion, which has high Z value `Z` for `H_(2) ^(o+) = 1, Z `"for" `H ^(o+) = 2` ` Z`" for" `D = 2, Z "for" Li^(2+) = 3` |
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| 661. |
If uncertainity in position of electron is `0.33 "pm"`. What will be uncertanity in its velocity ? |
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Answer» `Delta x = 0.33xx10^(-12)m^(-1)` `Delta v =(0.33xx10^(-12)) ge (h)/(4pi)= (6.626xx10^(-34))/(4xx3.14)` `implies Delta v ge 1.75xx10^(8)m//s` |
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| 662. |
Which statements are correct ?A. The enrgies of the vaious subl-levels in the sme shell fo H-atom are in rodes ` sgt pgt dgt f`B. s-orbital is no-directionalC. Electrons in moton behave as if they are waves .D. an orbitla can accomodatie a maximum of two electrons with paralledl spins . |
| Answer» Correct Answer - B::C | |
| 663. |
Which sets of quantum no. are consistent with the thory ?A. ` n= 2, l=1, m= 0, s=- 1//2`B. ` n=4, l=3 , m=- 2 s= - 1//2`C. ` n =3, l=3, m=- 2, s=- 1//2`D. ` n =3, l=3, m=- 2, s=- 1//2` |
| Answer» Correct Answer - A::B::D | |
| 664. |
Which of the following statements is wrong about athode rays?A. They travel in straight lines towards cathode.B. They produce heating effect.C. They carry negative charge.D. They produce X-rays when strike with material having high atomic masses. |
| Answer» Correct Answer - A | |
| 665. |
The ratio `e//m` i.e. specific , for a cathode rayA. varies with a gas in a discharge tubeB. is fixedC. varies with different electrodesD. is maximum if hydrogen is taken |
| Answer» Correct Answer - B | |
| 666. |
In the case of Compton effect, which of the following is applicabel?A. energy conservationB. Momentum conservationC. Charge conservationD. All of these |
| Answer» Correct Answer - B | |
| 667. |
The number of orbitals in 3rd orbit areA. `3`B. `10`C. `18`D. None of these |
| Answer» Correct Answer - D | |
| 668. |
The orbital angular momentum of an electron in `2s`-orbital isA. `+(1)/(2).(h)/(2pi)`B. zeroC. `(h)/(2pi)`D. `sqrt2.(h)/(2pi)` |
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Answer» Correct Answer - B Orbital angular moment =`(h)/(2pi)sqrt(l(l+1))=0 ` For all s-obitsld t=0 |
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| 669. |
The energy levels of hypothetical one electron atom are shown below `e"____"n=oo` `-0.50eV"_____"n=5` `-1.45eV"_____"n=4` `-3.08eV"____"n=3` `-5.3eV"____"n=2` `-15.6eV"____"n=1`A. Find the ionisation potential of atom?B. Find the short wavelength limit of the series terminating at `n=2`?C. Find the wave no. of photon emitted for the transition made by the electron from third orbit to first orbit ?D. Find the minimum energy that an electron will have after interacting with this atom in the ground state, if the initial kinetic energy of the electron is (i) 6eV (ii) eV ? |
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Answer» Correct Answer - A::B::C::D (a) `I.P. =overset(DeltaE)(1=oo) =E_(oo) -E_(1)=0-(-15.6)=15.6.l.v`. (b) `n=oo" "n=2` `DeltaE = [0-(-5.3)]=5.3l.v`. `DeltaE =(1240)/(lambda(nm))" "lambda=(1240)/(5.3)=233.9nm` `(c ) |DeltaE_(3rarr1)|=|-3.08-(-15.6)|=15.6-3.08=12.52l.v.=(1240)/(lambda)=(12.52)/(1240)=(1)/(lambda)(n.m)` `lambda = 1.808xx10^(7)m^(-1)` (d) (i)`E=-15.6-(-6)=-15.6+6=-9.6` (ii) `E=-15.6-(-11)=-15.6+11=-4.6` |
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| 670. |
`IE_1` for `._1H^2` and ` IE_1` for `._1H^1` are related as ?A. `IE_1" "._1H^2 gt IE_1" "._1H^!`B. `IE_1 " "._1H^2 = IE_1" "._1H^!`C. `IE_1" ". _1H^2 lt IE_1" "._1H^!`D. `IE_1" ". _1H^2ge IE_1" "._1H^!` |
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Answer» Correct Answer - A Ionisation energu for heaviesr isotpe is more . |
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| 671. |
The dissociation energy of `H_(2)` is `430.53 kJ mol^(-1), `If `H_(2)` is of dissociated by illumination with radiation of wavelength `253.7 nm` , the fraction of the radiant energy which will be converted into ikinetic energy is given by |
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Answer» Correct Answer - `8.68%` Energy required to break H-H bond `=(430.53xx10^(3))/(6.023xx10^(23))J//"molecule" =7.15xx10^(-19)J` Energy of photon used for this purpose `=(hc)/(lambda)` `=(6.625xx10^(-34)xx3.0xx10^(8))/(253.7xx10^(-9))=7.83xx10^(-19)J` `therefore` Energy left after dissociation of bond `=(7.83-7.15)xx10^(-19)` or " "Energy converted into `K.E.=0.68xx10^(-19)J` `therefore %` of energy used in kinetic energy `=(0.68xx10^(-19))/(7.83xx10^(-19))xx100=8.68%` |
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| 672. |
Photons havings `3^(rd)` highest energy of this sample can be used to excited particular excited state of `LI^(+2)`, thenA. Wavelenght of photon used for this transition is 121.5 nmB. Final excitd state of `Li^(+2)` is 6C. kinetic energy of electron in intaial excited state of `Li^(+2)` is 13.6 eVD. All are correct |
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Answer» Correct Answer - D `3^(rd)` highest energetic photons `rArr(13.6-3.4) eV=10.2 eV`, transition is `2 to 1` `lambda=(hc)/(E)=(1240)/(10.2)nm` = `121.5nm` For H atom = for `Li^(+2)` ion `13.6xx1[1-(1)/(2^(2))] =13.6xx9[(1)/(3^(2))-(1)/(6^(2))]` `therefore`for `Li^(+2)` ion tramsition is `3 to 6` Initial excited state =3 Final excited state =6 K.E. of electron in initial excited state of `L^(+2)`= `13.6xx(3^(2))/(3^(2))`=`13.6 eV` |
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| 673. |
Doubly magic nucleus is …A. `._82Pb^207`B. `._82Pb^206`C. `._82Pb^208`D. `._83Pb^209` |
| Answer» Correct Answer - C | |
| 674. |
Alveoli are tiny sacs in the lungs whose average diamter is `5xx10^(-5)m`. Consider an oxygen molecule `(5.3xx10^(-26)kg)` trapped within a sac. Calculate uncertainty in the velocity of oxygen molecule. |
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Answer» Uncertainty in position `Deltax=` Diameter of Alveoli `=5xx10^(-10)m` `Deltax Deltav ge(h)/(4pim)` `Deltavge(6.626xx10^(-34))/(4xx3.14xx5.3xx10^(-26)xx5xx10^(-10))` `Deltav~~1.99m//sec`. |
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| 675. |
For particles having same kinetic energy , the de Brogle wavelenght is-A. Directly propertioanl to its velocityB. Inversely proportial to its velcotiyC. indepenedent of velocity and massD. Unperdicatable |
| Answer» Correct Answer - A | |
| 676. |
Which of the following statements is wrong for H-like atom ?A. Magnitude of energy of an orbit in H-like species is directly proportional to `1//n^(2)`B. Frequency of revolution of an electron in an orbit is proportional to `n^(3)`C. Radius of a Bohr orbit is proportional to `n^(2)`D. Time period of revolution of an electron is proportional to `n^(3)` |
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Answer» Correct Answer - B |
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| 677. |
The frequency of light emitted for the transition `n = 4` to `n =2` of `He^+` is equal to the transition in `H` atom corresponding to which of the following ?A. `n=3` to `n=1`B. `n=2` to `n=1`C. `n=3` to `n=2`D. `n=4` to `n=3` |
| Answer» Correct Answer - B | |
| 678. |
In how many elements does the electron have the quantum number of n =4 and l = 1 ?A. 4B. 6C. 8D. 10 |
| Answer» Correct Answer - 2 | |
| 679. |
The spectrum of `He` is expected to be similar to that ofA. `Li^(2+)`B. HeC. HD. Na |
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Answer» Correct Answer - A::C |
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| 680. |
What are possible values of `m_(s)` for an electron with `m_(l)=0` ? |
| Answer» Correct Answer - `m_(s)` must be `-1//2` or `+1//2`. These are the only permitted values, regardless of the values of the other quantum numbers. | |
| 681. |
What is the angular velocity `(omega)` of an electron occupying second orbit of `Li^(2+)` ion?A. `(8pi^(3)me^(4))/(h^(3))K^(2)`B. `(8pi^(3)me^(4))/(9h^(3))K^(2)`C. `(64)/(9) xx (8pi^(3)me^(4))/(9h^(3))K^(2)`D. `(9pi^(3)me^(4))/(h^(3))K^(2)` |
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Answer» Correct Answer - D `omega_(n,z) = 2pi f_(n,z) = (V_(n,z))/(r_(n,z))` |
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| 682. |
The hydrogen atom in the ground state is excited by means of monochromatic radiation of wavelength `xA_(0)` The resulting spectrum consists of 15 different lines. Calculate the value of x. |
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Answer» Correct Answer - `938A^(@)` `(n(n-1))/(2)=15" "n^(2)-n=30` `n^(2)-n-30=0" "n=6` `(1)/(lambdaÅ)=R_(H)[(1)/(1)-(1)/(36)]` `(1)/(x)=(1)/(912)xx(35)/(36)=(35xx2496)/(32832)` `lambda=932Å` |
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| 683. |
Choose the correct statement among the following:A. `psi^(2)` represents the atomic orbitalB. The number of peaks in radial distribution is n-1C. A node is a point in space around nucleus where the wave function `psi` has zero valueD. All of the these |
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Answer» Correct Answer - D All are correct |
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| 684. |
In Bohr model of the hydrogen atom, let R,v and E represent the radius of the orbit, speed of the electron and the total energy respectively. Which of the following quantities are directly proportional to the quantum number n?A. `rE`B. `vr`C. `(v)/(E)`D. `(r)/(E)` |
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Answer» Correct Answer - B::C `r prop (n^(2))/(z), v prop (z)/(n), E prop (-z^(2))/(n^(2))` |
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| 685. |
In a main energy level, the orbital with more number of nodal planes will be.......A. Higher energyB. Lower energyC. Either 1 or 2D. Neither 1 nor 2 |
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Answer» Correct Answer - A The orbital with more no. of nodal planes will have more energy. |
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| 686. |
Which of the following statements is not correct?A. The wave function depicting the dependence on r involves two quantum numbers n and 1B. The wave function depicting the angular dependence involves two quantum numbers 1 an mC. The spin quantum number is not the outcome of the Schrodinger equation.D. The lowest energy state of an atom corresponds to `n = 0` |
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Answer» Correct Answer - D `n = 0` is not possible. |
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| 687. |
The ratio of magnetic moments of `Fe(III)` and `Co(II)` is:A. `sqrt(5):sqrt(7)`B. `sqrt(35):sqrt(15)`C. `7:3`D. `sqrt(24):sqrt(15)` |
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Answer» Correct Answer - B `mu_(s) = sqrt(n(n+2)) BM` In `Fe(III), n = 5`, In `CO(II), n = 3` |
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| 688. |
The ratio of magnetic moments of `Fe(III)` and `Co(II)` is `:`A. `sqrt(5):sqrt(7)`B. `sqrt(35):sqrt(15)`C. `7:3`D. `sqrt(24):sqrt(15)` |
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Answer» Correct Answer - 2 `Fe(III)[Ar]3d^(5),` unpaired electron`=5,` magnetic moment `=sqrt(5(5+2))BM` `CO(II)-[Ar]3d^(7),` unpaired electrons `=3,` magnetic moment `=sqrt(3xx(3+2))BM` |
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| 689. |
If a hydrogen atom emit a photon of energy `12.1 eV` , its orbital angular momentum changes by `Delta L. then`Delta L` equalsA. `1.05xx10^(-34)J" "sec`B. `2.11xx10^(-34)J" "sec`C. `3.16xx10^(-34)J" "sec`D. `4.22xx10^(-34)J" "sec` |
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Answer» Correct Answer - B Emission of photo of 12.1 eV corresponds to the `therefore` Change in angular momantum `=(n_(2)-n_(1))(h)/(2pi)` `=(3-1)(h)/(2pi)=(h)/(pi)` `=(6.626xx10^(-34))/(3.14)=2.11xx10^(-34)J" "sec` |
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| 690. |
`""_(8)X^(16) and ""_(8)X^(17)` representA. IsotonesB. IsobarsC. IsotopesD. Isosters |
| Answer» Correct Answer - C | |
| 691. |
Why is Rutherford model called a nuclear model ? |
| Answer» Discovery of nucleus | |
| 692. |
Why did Thomson assume that electrons are embedded in a positive mass but not the other way round ? |
| Answer» Thomson assumed that electrons are embedded in a positive mass as it could explain several observations like only electrons are ejected when a metal is heated and never positively charged particles. | |
| 693. |
The electrons in a poly -electronic atom are filled one by one in roder fo increasing energy level . The enrgy fo subsgells and orientation depeds upon the values of three quantum numbers 9 i.e., n. l and m respectively derived from Schrodinger wave equation . The different orbitals fo a subsshells however possess same energy level and are called degenerater orbitals but their enrgy level charges in presenct of magentic field and the orbitals are non-degenerate . (A) spectral line is noticed it an electron jups form one level to tohere . the paramgnetic nature of eelment sis due to the presence of unpaired electron . The number of spherical and angular nodes in ` 2p` orbitals are :A. `1,1`B. `2,1`C. `1,0`D. `0,1` |
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Answer» Correct Answer - D 2p has ` n= 2 , l=1` Spheircal node ` =n -l -1 =0` angualr node ` =l=1`. |
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| 694. |
Ioline molecule dissociated into atom after abesrbing light of `4500 Å` If can quantum of radiation is absorbed by each molecule, energy of `l_(2) = 240 kJ mol^(-1)` |
| Answer» Correct Answer - A::C::D | |
| 695. |
The radius of hydrogen atom in its ground state is `5.3 xx 10^-11 m`. After collision with an electron it is found to have a radius of `21.2 xx 10^-11 m`. The principal quantum number of the final state of the atom is.A. 2B. 3C. 4D. 5 |
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Answer» Correct Answer - A (a) Radius of `H^-` atoms in its ground state, `r_1 = 5.3 xx 10^-11 meters` Radius of Bohr atom in its nth orbit, `r_n = 5.3 xx 10^-11 (n^2)/(z) meters` For `H-"atom"`, `z=1` and `rn = 2.2 xx 10^-11 meters` `n = ((21.2 xx 10^-11)/(5.3 xx 10^-10))^(1//2) = 2`. |
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| 696. |
Which element has a hydrogen like spectrum whose lines have wavelength one fourth of atomic hydrogen ?A. `He^(+)`B. `Li^(2 +)`C. `Be^(3 +)`D. `B^(4 +)` |
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Answer» Correct Answer - A (a) `(1)/(lamda_H) = R xx 1^2 ((1)/(n_1^2) -(1)/(n_2^2))` ....(i) `(1)/(lamda_X) = RZ^2 ((1)/(n_1^2) -(1)/(n_2^2))` ....(ii) Dividing equation (i) by equation (ii), we get =`(lamda_x)/(lamda_H) = (1)/(Z^2)` `(1)/(4) = (1)/(Z^2)` `Z = 2 (He^+)`. |
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| 697. |
The electrons in a poly -electronic atom are filled one by one in roder fo increasing energy level . The enrgy fo subsgells and orientation depeds upon the values of three quantum numbers 9 i.e., n. l and m respectively derived from Schrodinger wave equation . The different orbitals fo a subsshells however possess same energy level and are called degenerater orbitals but their enrgy level charges in presenct fo magentic field and the orbitals are non-degenerate . (A) spectral line is noticed it an electron jups form one level to tohere . the paramgnetic nature of eelment sis due to the presence of unpaired electron . The possible muber of spectral lines when an eelcron can jump `5th` shell to 2nd shell is :A. `4`B. `2`C. `3`D. `6` |
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Answer» Correct Answer - D No. of lines ` = sum Delta n = = sum 5 - 5 2 = sum 3 =6`. |
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| 698. |
The electrons in a poly -electronic atom are filled one by one in roder fo increasing energy level . The enrgy fo subsgells and orientation depeds upon the values of three quantum numbers 9 i.e., n. l and m respectively derived from Schrodinger wave equation . The different orbitals fo a subsshells however possess same energy level and are called degenerater orbitals but their enrgy level charges in presenct of magentic field and the orbitals are non-degenerate . (A) spectral line is noticed it an electron jups form one level to to here . the paramgnetic nature of eelment sis due to the presence of unpaired electron . The coarrect orde for menry levels in H-atom is ?A. ` 3s = 3 p = 3d = gt 2s`B. ` 3d gt 3p gt 3s gt 2s`C. ` 3s gt 3p gt 3s gt 2s`D. `3d gt 3p gt 3s =2s` |
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Answer» Correct Answer - A The different subsdhells of a shwll in H-atom possess same wsengy . |
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| 699. |
In ` s_1` be the specific charge `( e//m)` of cathode rays and `(S_2)` be that of positive rays , then which is true ?A. `S_(1) = S_(2)`B. `S_(1) gt S_(2)`C. `S_(1) lt S_(2)`D. Any one of these |
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Answer» Correct Answer - B mass of electron is less |
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| 700. |
`""_(x)^(y)A, _(x)^(y+1)A` are two isotopes of element A. Difference between number of neutrons in the isotopes isA. 1-2yB. 1-xC. 1D. 2x-1 |
| Answer» Correct Answer - C | |