Atomic Structure — JEE Main PYQs

If the wavelength for an electron emitted from H atom is 3.3 × 10⁻¹⁰ m, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is _____ times. (Nearest integer).
[Given: h = 6.626 × 10⁻³⁴ Js, Mass of electron = 9 …

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.
Reason R: Energies of the orbitals in the same subshell decrease with increase …

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

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

When the excited electron of a H atom from $\mathrm{n}=5$ drops to the ground state, the maximum number of emission lines observed are _____

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 $9.1\times 10^{-31}\mathrm{kg}$ and mass of neutron is …

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

Consider the following sets of quantum numbers:

The number of correct sets of quantum numbers is ______.

If the work function of a metal is $6.63\times 10^{-19}$ J, 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 $c=3\times 10^8$ m s${}^{-1}$]

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

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

Which of the following statements are correct?
(A) The electronic configuration of Cr is $[\mathrm{Ar}]3{\mathrm{d}}^{5}4{\mathrm{s}}^1$.
(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 i …

The electronic configuration of Pt (atomic number 78) is:

If the radius of the $3^{\text{rd }}$ Bohr's orbit of hydrogen atom is $r_3$ and the radius of $4^{\text{th }}$ Bohr's orbit is $r_4$. Then :

If the uncertainty in velocity and position of a minute particle in space are, $2.4\times 10^{-26}({\mathrm{ms}}^{-1})$ and $10^{-7}(\mathrm{m})$ respectively. The mass of the particle in g is ______ (Nearest integer)
(Given : $\mathrm{h}=6.626\times 10^{-34}\mathrm{Js}$)

The minimum uncertainty in the speed of an electron in an one dimensional region of length $2a_O$ (Where $a_0=$ Bohr radius 52.9 pm) is ______ $\mathrm{km}{\mathrm{s}}^{-1}$.
(Given: Mass of electron $=9.1\times 10^{-31}\mathrm{kg}$, Planck's constant …

Consider the following pairs of electrons
(A) (a) $\mathrm{n}=3,1=1,{\mathrm{m}}_1=1,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$
(b) $\mathrm{n}=3,1=2,{\mathrm{m}}_1=1,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$
(B) (a) …

The energy of one mole of photons of radiation of wavelength 300 nm is
(Given : $\mathrm{h}=6.63\times 10^{-34}$ Js, ${\mathrm{N}}_{\mathrm{A}}=6.02\times 10^{23}$ mol${}^{-1}$, c $=3\times 10^8$ ms${}^{-1}$ )

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 $1.3\times 10^{15}{\mathrm{s}}^{-1}$ and $\mathrm{h}=6.6\times 10^{-34}\mathrm{J}\mathrm{s}$.]

The pair, in which ions are isoelectronic with ${\mathrm{Al}}^{3+}$ is :-

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

A proton and a ${\mathrm{Li}}^{3+}$ nucleus are accelerated by the same potential. If ${\lambda }_{\mathrm{Li}}$ and ${\lambda }_{\mathrm{p}}$ denote the de Broglie wavelengths of ${\mathrm{Li}}^{3+}$ and proton respectively, then the value of …

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 the nucleus.
Statement II: According to …

A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric current is $4.3\times 10^{14}\mathrm{Hz}$. The velocity of ejected electron is $\_\_\_\_$ $\times 10^5{\mathrm{ms}}^{-1}$.
(Nearest integer)
[Use: …

The Azimuthal quantum number for the valence electrons of ${\mathrm{Ga}}^{+}$ion is ____.
(Atomic number of Ga=31)

According to Bohr's atomic theory:
(A) Kinetic energy of electron is $\propto \frac{z^2}{n^2}$
(B) The product of velocity ( v ) of electron and principal quantum number ( n ) ' vn ' $\propto {\mathrm{Z}}^2$
(C) Frequency of revolution of electron in an orbit is …

The wavelength of electrons accelerated from rest through a potential difference of 40 kV is $x\times 10^{-12}\mathrm{m}$. The value of $x$ is ______. (Nearest Integer)
Given: Mass of electron $=9.1\times 10^{-31}\mathrm{kg}$
Charge on an electron …

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 $x\times 10^{13}$. The value of $x$ is ____. (Nearest integer)
( …

The Plots of radial distribution functions for various orbitals of hydrogen atom against '$r$' are given below:

(a) (see plot)
(b) (see plot)
(c) (see plot)
(d) (see plot)

The correct plot for 3s orbital is:

Number of electrons that Vanadium ($\mathrm{Z}=23$) has in p-orbitals is equal to _____

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

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $\frac{h^2}{xm{a}_0^2}$. The value of $10x$ is ______. ($a_0$ is radius of Bohr's orbit) (Nearest integer)
[Given : $\pi =3.14$]

A ball weighing 10 g is moving with a velocity of $90{\mathrm{ms}}^{-1}$. If the uncertainty in its velocity is $5\%$, then the uncertainty in its position is ____ $\times 10^{-33}\mathrm{m}$. (Rounded off to the nearest integer)
[Given: …

The value of magnetic quantum number of the outermost electron of ${\mathrm{Zn}}^{+}$ ion is ______.

$\mathrm{Ge}(\mathrm{Z}=32)$ in its ground state electronic configuration has $x$ completely filled orbitals with ${\mathrm{m}}_{\mathrm{l}}=$ 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's uncertainty principle.
In the light of the above statements, choose the most appr …

A certain orbital has $n=4$ and $m_{\ell }=-3$. The number of radial nodes in this orbital is ______. (Round off to the nearest integer).

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, $x\times 10^{20}$ electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from t …

An accelerated electron has speed of $5\times 10^6{\mathrm{ms}}^{-1}$ with an uncertainty of $0.02\%$. The uncertainty in finding its location while in motion is $x\times 10^{-9}\mathrm{m}$. The value of $x$ is ____.
(Nearest integer)
[Use mass of electron …

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

A 50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons emitted per second by the bulb is $x\times 10^{20}$. The value of $x$ is ______.
[Given: $\mathrm{h}=6.63\times 10^{-34}\mathrm{Js}$ and $\mathrm{c}=3.0\times 10^8{\mathrm{ms}}^{-1}$ …

When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV , the de-Broglie wavelength of emitted electrons is ____ $\stackrel{\circ }{A}$.
(Round off to the nearest Integer). [Use : …

The number of orbitals with $\mathrm{n}=5,{\mathrm{m}}_{\mathrm{l}}=+2$ is ______. (Round off to the nearest integer).

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 the light of the above statements, choo …

The number of orbitals associated with quantum number $n=5$, $m_s=+\frac{1}{2}$ is

For the Balmer series in the spectrum of H atom, $\bar{v}={\mathrm{R}}_{\mathrm{H}}\left\{\frac{1}{{\mathrm{n}}_1^2}-\frac{1}{{\mathrm{n}}_2^2}\right\}$ the correct statements among (I) to (IV) are :
(I) As wavelength decreases, the lines in the series converge
(II) The integer …

The radius of the second Bohr orbit, in terms of the Bohr radius, ${\mathrm{a}}_0$, in ${\mathrm{Li}}^{2+}$ is

The de Broglie wavelength of an electron in the $4^{\text{th}}$ Bohr orbit is: