Given r n + 1 − r n − 1 = 2 r n , where r n , r n − 1 , r n + 1 are Bohr radius for hydrogen atom in n th ,(n-1) th and (n+1) th shell respectively. Calculate the value of n.
For a given principal level n = 4, the energy of its subshells is of the order
The velocity of electron ejected from platinum surface is 6 . 54 × 10 x m/s when radiation of 200 nm falls on it. Work function of platinum is 5 eV . 1 eV = 1.6 × 10 − 19 J . The value of x is
Select the correct set (s) of quantum numbers
Let A n be the area enclosed by the nth orbit in a hydrogen atom. The graph of ln ( A n / A 1 ) against ln(n): (Here A1 is the first orbit.)
wavelength of 400 nm corresponds to
An orbital has only positive values of wave function at all distances from nucleus. The (n + l ) of this orbital is:
When an electron makes transition from (n+1) state to ‘n’ state ,the wavelength of emitted radiations is related to ‘n’ according to λ ∞ n x . The value of ‘X’ if n >>>>>1 is ———————
The ionization energy of H is 13.6 electron volts (eV). The first and second ionization energies of He must be approximately.
Out of the following, how many of them have magnetic moment value 24 BM . Ti 2 + , Ti 3 + , V 2 + , Cr 2 + , Cr 3 + , Mn 2 + , Fe 2 +
The mass of an electron is m, charge is e and it is accelerated from rest through a potential difference of V volts. The velocity acquired by electron will be
A hydrogen atom in its ground state is irradiated by light of wavelength 970 A o . Taking hc/e = 1.237 × 10 -6 eV m and the ground state energy of hydrogen atom as -13.6 eV, the number of lines present in the emission spectrum is
Which is / are correct statement?
What is the maximum number of emission lines when the excited electron of a H-atom in n = 4 drops to the ground state?
How many electrons in an atom can have n = 3 , l = 1 ?
An element with atomic number 16 has only one electron. Which orbit of it is equal in size to I orbit of H?
How many electrons will reside in ‘g’ orbital if an element with atomic number 127 is discovered?
The distance between 4 th and 3 rd Bohr orbits of He + is
The angular momentum of electron can have the value (s)
What is the total number of radial and angular nodes present in 5f orbital?
Select the correct statement(s)
Atomic mass of He and Ne are 4 and 20 amu respectively. The value of the de Broglie wavelength of He gas -73°C is “M” times that of the de-Broglie wavelength of Ne at 727°C. M is
In a sample of H-atoms electrons are de-excited from 4th excited state to ground state. Which is / are correct statement?
FM radio broadcasts at 900 kHz. The wavelength it corresponds to is meter ? Round off to nearest integer.
What is the maximum number of orbitals that can be identified with the following quantum numbers? n = 3, l = 1 , m l = 0
Select the correct configuration(s) of the given species If Aufbau rule is not followed
Ground state configuration of nitrogen atom can be represented by:
Which statements are correct ?
Select the correct statement for electron denoted by n = 4 and m = -2:
Which of the following species has/have five unpaired electrons ?
Which of the following orbitals has (have) one spherical node?
A species having only one electron has ionization energy of 11810 kJ mol. The number of proton in its nucleus is
1 mole of photons, each of frequency 250 sec -1 would have approximately a total energy (in erg):
In an atom, the total number of electrons having quantum numbers n = 4 , m l = 1 and m s = − 1 / 2 is :
Find number of pairs in which difference between total number of electrons is zero. N 2 O , CO 2 NO 2 + , CO 2 NH 3 , PH 4 + Cr 6 + , Sc 3 + Se 2 − , Br − NO 2 + , O 3 ( i ) ( ii ) ( iii ) ( iv ) ( v ) ( vi )
Number of lobes present in d z 2 orbital is
One molecule of a substance absorbs one quantum of energy. The energy involved when 1.5 mole of the substance absorbs red light of frequency 7.5 × 10 14 sec − 1 will be
In Millikan’s experiment, static electric charge on the oil drops has been obtained by shining X-rays. If the static electric charge on the oil drop is -1.282 × 10 18 C calculate the number of electrons present on it.
Which of the following species has/have five unpaired electrons?
At 200°C,hydrogen molecule have velocity 2.4 × 10 5 cm s -1 . The de Broglie wavelength in this case is approximately
Which is a possible set of quantum numbers for a valence unpaired electrons in ground state atom of phosphorus (Z = 15)
Hamiltonian operator H ^ is the sum of two energy operators. These are
Five valence electrons of 15 30 P are labeled as If the spin quantum number of q and z is +(1/2), then the group of electrons with three of the quantum number same are
Let A n be the area enclosed by the nth orbit in a hydrogen atom. The graph of ln ( A n / A 1 ) against ln(n): (Here A1 is the first orbit.)
A certain transition in H spectrum from an excited state to ground state in one or more steps gives rise to total 10 lines. How many of these belong to UV spectrum?
Match the species in Column I with their related properties in Column II.(Atomic Number is indicated in brackets in Column-I)
Consider following curve for electron of H-atom The orbital(s) belonging to above curve can also be described by curve(s):
Photons of energy 7 eV are incident on two metals A and B with work functions 6 eV and 3 eV respectively. The minimum de-Broglie wavelengths of the emitted photoelectrons with maximum energies are λ A and λ B , respectively where λ A λ B is equal to .
Orbital angular momentum of an electron is 3 h π then the number of possible orientations of this orbital in space is:
The spin only angular momentum of unpaired electron in copper atom is
Total energy of an atom when electron is in the 1st orbit of hydrogen atom is -13.6eV/atom. Kinetic energy of electron in the 1st excited state of Li 2+ ion in eV is:
The angular momentum of an electron in 4s orbital, 3p orbital, and 4th orbit are
The magnetic moment of KO 2 at room temperature is BM.
A certain transition in H spectrum from an excited state to ground state in one or more steps gives rise to total 10 lines. How many of these belong to UV spectrum ?
The energy of an electron in the first energy level of H atom is -13.6 eV. The possible energy value (s) of the excited state (s) for the electron in He + is (are).
The spin magnetic moment of tetracyanonickelate (II) ion is B.M
Select the correct statement(s)
An α -particle moving with velocity 1 30 th times velocity of light. If uncertainty in position is 3 . 31 π pm, then minimum uncertainty in kinetic energy y × 10 -16 J. Calculate the value of y.
If in Bohr’s model, for unielectronic atom, time period of revolution is represented as T n,z where n represents shell no. and Z represents atomic number then the value of T 1,2 : T 2,1 will be
If the ionization energy of He + is 19.6 × 10 -18 J per atom then the energy of Be 3+ ion in the second stationary state is:
Which series of subshells is arranged in the order of increasing energy for multi-electron atoms?
Choose the correct statements among the following
Select the correct statement(s)
When an electron makes transition from (n + 1) state to n state the wavelength of emitted radiations is related to n (n>>>1) according to λ ∝ n x . The value of x is
Choose the correct statements among the following
A gas absorbs photon of wavelength 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm, the other is at
Which of the following rules / principles not responsible to rule out the existence of definite paths or trajectories of electrons?
In Lyman series, shortest wavelength of H-atom appears at x meter , then longest wavelength in Balmer series of He + appear at
Werner Heisenberg considered the limits of how precisely we can measure the properties of an electron or other microscopic particle. He determined that there is a fundamental limit to how closely we can measure both position and momentum. The more accurately we measure the momentum of a particle, the less accurately we can determine its position. The converse is also true. This is summed up in what we now call the Heisenberg uncertainty principle. The equation is Δx ⋅ Δ ( mv ) ≥ h 4 π The uncertainty in the position or in the momentum of a macroscopic object like a baseball is too small to observe. However, the mass of microscopic object such as an electron is small enough for the uncertainty to be relatively large and significant.
If an atom, the total number of electrons having quantum number n = 4, m l = 1 and m s = − 1 2 is
Not considering the electronic spin, the degeneracy of the second excited state (n = 3) of H-atom is 9, while the degeneracy of the second excited state of H – is . . . .
Select the correct statement(s)
The longest wavelength of light capable of breaking a single (C-CI) bond in Cl 2 is if Cl − Cl ( g ) ⟶ 2 Cl ( g ) ; ΔH = 242 kJ mol − 1
Calculate the energy in joule corresponding to light of wavelength 45 nm. (Planck’s constant, h = 6.63 × 10 – 34 Js , speed of light, c = 3 ×10 8 ms -1 )
The ground state energy of hydrogen atom is – 13.6 eV. Consider an electronic state ψ of He + whose energy, azimuthal quantum number and magnetic quantum number are – 3.4 eV, 2 and 0, respectively. Which of the following statement(s) is (are) true for the state ψ ?
The ground state energy of hydrogen atom is – 13.6 eV. Consider an electronic state Y of He + whose energy, azimuthal quantum number and magnetic quantum number are – 3.4 eV, 2 and 0, respectively. Which of the following statement(s) is (are) true from the state Y ?
The potential energy of an electron in the second Bohr’s orbit of the He + ion is x, Which cant be value x in this case ?
If the radius of the first Bohr orbit is x, then de-Broglie wavelength of the electron in the third orbit is nearly
Quantum numbers have been matched with their characteristics. Select correct matching(s).
The ionisation energy of hydrogen atom is 13.6 eV and the first ionisation energy of helium is 24.6 eV
The ratio of the energy of a photon of 2000 Å wavelength radiation to that of 4000 Å radiation is
How many electrons in an atom can have n = 3 , l = 1 ?
The first excitation energy of H-like atom is 40.8 eV. The atomic number of element is:
An orbital has only positive values of wave function at all distances from nucleus. The (n + l ) of this orbital is
The sum of angular node and radial node of 4d xy atomic orbital.
The radiations obtained from deexcitation of H-atom from second orbit to 1st, striked on a metal of work function ϕ 4.2 eV. The wavelength (in A o ) of ejected electron having maximum kinetic energy is:
The longest wave length of that can cause photoelectric emission from a metal surface is 310 nm. The work function of metal in e.V. is:
Which of the following electro magnetic radiation is consisting of matter particle
The probability of finding the electron in p x -orbital is:
Which statements concerning Bohr’s model are true?
The letters n, I and m proposed by Bohr, Sommerfeld and Zeeman respectively for quantisation of angular momentum in classical physics were later on obtained as the results of solution of Schrödinger wave equation based on quantum mechanics. The term n, l , m were named as principal quantum number, azimuthal quantum number and magnetic quantum number respectively. The fourth quantum number i.e., spin quantum number, s was given by Uhlenback on the basis of two spins of electrons. The first two quantum numbers also decides the nodes of an orbital.
Which of the following statement(s) is/are correct?
The sets of quantum numbers allowed are
The ratio of the energy of a photon of 2000 A o wavelength radiation to that of 4000 A o radiation is
When the electron of a hydrogen atom jumps from n = 4 to n =1 state, the number of spectral lines emitted is:
For principal quantum number n = 4, the total number of orbitals having l = 3 is
The maximum number of electrons in an atom that can be have quantum numbers n = 4 , m l = + 1 is
3 p x orbital and 4 p x orbital of an atom hwill not have same
How many electrons in an atom can have n = 3 , l = 1 ?
An element with atomic number 16 has only one electron. Which orbit of it is equal in size to Ist orbit of H?
How many electrons in an atom can have n = 3 , l = 1 ?
If electrostatic potential energy between the two electrons is 7.67 × 10 − 19 J . What is their distance of separation (in A o ) in vacuum?
Sodium and Copper have work functions 2.3 eV and 4.6 eV respectively. The minimum wave lengths ratio responsible to knock out electron is nearest to
The no. of waves made by an electron during its revolution in 5 th orbit is
Two atoms are said to be isobars if
The pair of ions having same electronic configuration is
An electric bulb is rated 220 volt -100 watt. The power consumed by it when operated on 110 volt will be
Given, ΔE = R ¯ H Z 2 1 n 1 2 − 1 n 2 2 R H (Rydberg constant) for H-atom is x m -1 . Corresponding value for this constant for He + ion is
Which of the following orbitals has(have) one spherical node?
Ground state electronic configuration of nitrogen atom can be represented as
Which of the following orbitals has (have) one spherical node?
The transition of electrons in H atom that will emit maximum energy is
A species having only one electron has ionization energy of 11810 kJ mol -1 . The number of proton in its nucleus is
Which of the following properties can be described by wave function ψ ?
There is formation of in all five nodes (including terminal nodes) in a string of 12 cm. Thus, wavelength of the waves formed is
ψ 2 at any point is proportional to
Angular nodes in 4s- suborbit is equal to radial nodes in
