Structure of Atom

Which of the following statements are correct?
(A) The electronic configuration of Cr is [Ar] 3d5 4s1.
(B) The magnetic quantum number may have a negative value.
(C) In the ground state of an atom, the orbitals are filled in order of their ...

Which of the following is the correct plot for the probability density \({\psi ^2}\) (r) as a function of distance 'r' of the electron from the nucleus for 2s orbital?

The minimum uncertainty in the speed of an electron in an one dimensional region of length \(2 \mathrm{a}_{\mathrm{o}}\) (Where \(\mathrm{a}_{\mathrm{o}}=\) Bohr radius \(52.9 \,\mathrm{pm}\)) is _________ \(\mathrm{km} \,\mathrm{s}^{-1}\)....

Given below are the quantum numbers for 4 electrons.
A. \(\mathrm{n}=3,l=2, \mathrm{~m}_{1}=1, \mathrm{~m}_{\mathrm{s}}=+1 / 2\)
B. \(\mathrm{n}=4,l=1, \mathrm{~m}_{1}=0, \mathrm{~m}_{\mathrm{s}}=+1 / 2\)
C. $$\mathrm{n}=4,l=2, \mathrm{~m}_...

If the work function of a metal is 6.63 \(\times\) 10\(-\)19J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ____________ nm. (Nearest integer)
[Given : h = 6.63 \(\times\) 10\(-\)34 J s, and c = ...

Consider the following statements :
(A) The principal quantum number 'n' is a positive integer with values of 'n' = 1, 2, 3, ...
(B) The azimuthal quantum number 'l' for a given 'n' (principal quantum number) can have values as 'l' = 0, 1, ...

Identify the incorrect statement from the following.

If the wavelength for an electron emitted from \(\mathrm{H}\)-atom is \(3.3 \times 10^{-10} \mathrm{~m}\), then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is _______...

Given below are two statements: One is labelled as Assertion \(\mathbf{A}\) and the other is labelled as Reason \(\mathbf{R}\)
Assertion \(\mathbf{A}\) : Zero orbital overlap is an out of phase overlap.
Reason \(\mathbf{R}\) : It results du...

If the uncertainty in velocity and position of a minute particle in space are, 2.4 \(\times\) 10\(-\)26 (m s\(-\)1) and 10\(-\)7 (m) respectively. The mass of the particle in g is ____________. (Nearest integer)
(Given : h = 6.626 $$\times$...

Consider the following set of quantum numbers.

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Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Energy of \(2 \mathrm{s}\) orbital of hydrogen atom is greater than that of \(2 \mathrm{s}\) orbital of lithium.
Reason R: En...

Outermost electronic configurations of four elements A, B, C, D are given below :
(A) \(3 s^{2}\)
(B) \(3 s^{2} 3 p^{1}\)
(C) \(3 s^{2} 3 p^{3}\)
(D) \(3 s^{2} 3 p^{4}\)
The correct order of first ionization enthalpy for them is :

The correct decreasing order of energy for the orbitals having, following set of quantum numbers :
(A) n = 3, l = 0, m = 0
(B) n = 4, l = 0, m = 0
(C) n = 3, l = 1, m = 0
(D) n = 3, l = 2, m = 1
is :

If the radius of the 3rd Bohr's orbit of hydrogen atom is r3 and the radius of 4th Bohr's orbit is r4. Then :

The number of radial and angular nodes in 4d orbital are, respectively

The wavelength of an electron and a neutron will become equal when the velocity of the electron is \(x\) times the velocity of neutron. The value of \(x\) is ____________. (Nearest Integer)
(Mass of electron is $$9.1 \times 10^{-31} \mathrm...

Consider an imaginary ion \({ }_{22}^{48} \mathrm{X}^{3-}\). The nucleus contains '\(a\)'% more neutrons than the number of electrons in the ion. The value of 'a' is _______________. [nearest integer]

The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is x \(\times\) 10\(-\)8 m. The value of x is ___________. (Nearest Integer).
(Given : Energy of the electron in the first shell of...

The pair, in which ions are isoelectronic with AI3+ is :

The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is :
[Given : The threshold frequency of platinum is 1.3 \(\times\) 1015 s\(-\)1 and h = 6.6 \(\times\) 10\(-\)34 J s.]

Which of the following sets of quantum numbers is not allowed?

When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are _____________.

Consider the following pairs of electrons
(A) (a) n = 3, \(l\) = 1, m1 = 1, ms = + \({1 \over 2}\)
      (b) n = 3, 1 = 2, m1 = 1, ms = + \({1 \over 2}\)
(B) (a) n = 3, \(l\) = 2, m1 = \(-\)2, ms = \(-\)\({1 \over 2}\)
      (b) n = 3, $$l$...

The energy of one mole of photons of radiation of wavelength 300 nm is (Given : h = 6.63 \(\times\) 10\(-\)34 J s, NA = 6.02 \(\times\) 1023 mol\(-\)1, c = 3 \(\times\) 108 m s\(-\)1)

Ge(Z = 32) in its ground state electronic configuration has x completely filled orbitals with ml = 0. The value of x is ___________.

Given below are two statements :Statement I : Rutherford's gold foil experiment cannot explain the line spectrum of hydrogen atom.Statement II : Bohr's model of hydrogen atom contradicts Heisenberg' uncertainty principle.In the light of the...

If the Thompson model of the atom was correct, then the result of Rutherford's gold foil experiment would have been :

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to \({{{h^2}} \over {xma_0^2}}\). The value of 10x is ___________. (a0 is radius of Bohr's orbit) (Nearest integer) [Given : \(\pi\) = 3.14]

The number of photons emitted by a monochromatic (single frequency) infrared range finder of power 1 mW and wavelength of 1000 nm, in 0.1 second is x \(\times\) 1013. The value of x is _____________. (Nearest integer)(h = 6.63 \(\times\) 10...

The orbital having two radial as well as two angular nodes is :

Which of the following forms of hydrogen emits low energy \(\beta\)- particles?

A ball weighing 10 g is moving with a velocity of 90 ms\(-\)1. If the uncertainty in its velocity is 5%, then the uncertainty in its position is ___________ \(\times\) 10\(-\)33 m. (Rounded off to the nearest integer)[Given : h = 6.63 $$\ti...

Given below are two statements.Statement I : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by ...

A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric current is 4.3 \(\times\) 1014 Hz. The velocity of ejected electron is ____________ \(\times\) 105 ms\(-\)1 (Nearest integer)[Use : h = 6...

A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x \(\times\) 1020 electrons are ejected per second. Assume that wavelength 400 nm is suffi...

An accelerated electron has a speed of 5 \(\times\) 106 ms\(-\)1 with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x \(\times\) 10\(-\)9 m. The value of x is ____________. (Nearest integer)[Use mass of...

The plots of radial distribution functions for various orbitals of hydrogen atom against 'r' are given below :
The correct plot for 3s orbital is :

Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization enegy of metal A in kJ mol\(-\)1 is __________. (Rounded off to the nearest integer)[h = 6.63 \(\times\) 10\(-\)34 Js, c = 3.00 ...

Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is _________. (Integer answer)(A) Li(B) Na(C) Rb(D) Cs

A proton and a Li3+ nucleus are accelerated by the same potential. If \(\lambda _{Li}\) and \(\lambda _p\) denote the
de Broglie wavelengths of Li3+ and proton respectively, then the value of
\({{{\lambda _{Li}}} \over {{\lambda _p}}}\) is ...

According to Bohr's atomic theory :(A) Kinetic energy of electron is \(\propto {{{Z^2}} \over {{n^2}}}\).(B) The product of velocity (v) of electron and principal quantum number (n), \('vn' \propto {Z^2}\).(C) Frequency of revolution of el...

The Azimuthal quantum number for the valence electrons of Ga+ ion is ___________.(Atomic number of Ga = 31)

The wavelength of electrons accelerated from rest through a potential difference of 40 kV is x \(\times\) 10\(-\)12 m. The value of x is ___________. (Nearest integer)Give : Mass of electron = 9.1 \(\times\) 10\(-\)31 kgCharge on an electro...

Outermost electronic configuration of a group 13 element, E, is 4s2, 4p1. The electronic configuration of an element of p-block period-five placed diagonally to element, E is :

A 50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons emitted per second by the bulb is x \(\times\) 1020. The value of x is __________. [Given : h = 6.63 \(\times\) 10\(-\)34 Js and c = 3.0 \(\times\) ...

A certain orbital has no angular nodes and two radial nodes. The orbital is :

Given below are two statements :Statement I : Bohr's theory accounts for the stability and line spectrum of Li+ ion.Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field.In th...

A certain orbital has n = 4 and mL = \(-\)3. The number of radial nodes in this orbital is ____________. (Round off to the Nearest Integer).

When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is _______\(\mathop A\limits^o\). (Round off to the Nearest Integer).[ Use : \(\sqrt 3\) = 1.73, h = 6.63 $$\times...