Atomic Structure — JEE Main PYQs

The value of Rydberg constant $({\mathrm{R}}_{\mathrm{H}})$ is $2.18\times 10^{-18}\mathrm{J}$. The velocity of electron having mass $9.1\times 10^{-31}\mathrm{kg}$ in Bohr's first orbit of hydrogen atom $=\dots \dots \dots \times 10^5{\mathrm{ms}}^{-1}$ (nearest …

In an atom, total number of electrons having quantum numbers $n=4,\left|m_1\right|=1$ and $m_s=-\frac{1}{2}$ is

Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is ______ × 10¹³ Hz (nearest integer).
[Given: Rₕ (Rydberg constant) = 2.18 × 10⁻¹⁸ J. h (Plank's constant) = 6.6 × 10⁻³⁴ J.s.]

For hydrogen atom, energy of an electron in first excited state is -3.4 eV, K.E. of the same electron of hydrogen atom is x eV. Value of x is ______ $\times 10^{-1}\mathrm{eV}$. (Nearest integer)

Wavenumber for a radiation having $5800\text{A˚}$ wavelength is $x\times 10{\text{cm}}^{-1}$. The value of $x$ is ____.

A hypothetical electromagnetic wave is show below.

The frequency of the wave is $\mathrm{x}\times 10^{19}\mathrm{Hz}$.
$\mathrm{x}=$ ______ (nearest integer)

Compare the energies of following sets of quantum numbers for multielectron system.
(A) $\mathrm{n}=4,1=1$
(B) $n=4,1=2$
(C) $\mathrm{n}=3,\mathrm{l}=1$
(D) $\mathrm{n}=3,\mathrm{l}=2$
(E) $\mathrm{n}=4,1=0$

Choose the correct answer from the options given below :

Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $10^{-15}\mathrm{m}$ is $\_\_\_\_$ $\times 10^9{\mathrm{ms}}^{-1}$ (nearest integer)
[Given : mass of electron …

The number of electrons present in all the completely filled subshells having $\mathrm{n}=4$ and $\mathrm{s}=+\frac{1}{2}$ is ____.
(Where $\mathrm{n}=$ principal quantum number and $\mathrm{s}=$ spin quantum number)

The number of radial node/s for 3p orbital is:

According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship between wavelength of electron ($\lambda$) and momentum of electron (p)?

Total number of ions from the following with noble gas configuration is ____. …

The correct set of four quantum numbers for the valence electron of rubidium atom (Z=37) is:

The ionization energy of sodium in $\mathrm{kJ}{\mathrm{mol}}^{-1}$. If electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium atom is ______.

Given below are two statements:

Statement-I: The orbitals having same energy are called as degenerate orbitals.
Statement-II: In hydrogen atom, 3p and 3d orbitals are not degenerate orbitals.
In the light of the above statements, choose the most appropriate answer from the optio …

The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are

Number of spectral lines obtained in ${\mathrm{He}}^{+}$spectra, when an electron makes transition from fifth excited state to first excited state will be

Match List I with List II:
List-I (Element): A. N B. S C. Br D. Kr
List-II (Electronic Configuration): I. [Ar] 3d¹⁰ 4s² 4p⁵ II. [Ne] 3s² 3p⁴ III. [He] 2s² 2p³ IV. [Ar] 3d¹⁰ 4s² 4p⁶
Choose the correct answer from the options given below:

Given below are two statements: one is labelled as assertion and the other is labelled as reason.
Assertion: Loss of electron from hydrogen atom results in nucles of $\sim 1.5\times 10^{-3}$ pm size.
Reason: Proton $({\mathrm{H}}^{+})$ always exists in combined form

In the light …

The wavelength of an electron of kinetic energy $4.50\times 10^{-29}\mathrm{J}$ is...... $\times 10^{-5}\mathrm{m}$. (Nearest integer)

Given: mass of electron is $9\times 10^{-31}\mathrm{kg}$, $\mathrm{h}=6.6\times 10^{-34}\mathrm{J}\mathrm{s}$

If the radius of the first orbit of hydrogen atom ${\mathbf{a}}_0$, then de Broglie's wavelength of electron in $3^{\text{rd}}$ orbit is

Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is : (Given $\mathrm{v}=$ frequency of X -ray emitted; $\mathrm{Z}=$ atomic number)

The number of atomic orbitals from the following having 5 radial nodes is ____ .
$7\mathrm{s},7\mathrm{p},6\mathrm{s},8\mathrm{p},8\mathrm{d}$

The electron in the ${\mathrm{n}}^{\text{th}}$ orbit of ${\mathrm{Li}}^{2+}$ is excited to ($\mathrm{n}+1$) orbit using the radiation of energy $1.47\times 10^{-17}\mathrm{J}$ (as shown in the diagram). The value of $n$ is ______.

Given …

The number of following statement/s which is/are incorrect is ______
(A) Line emission spectra are used to study the electronic structure
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet
(C) An absorption spectrum is lik …

The number of incorrect statement/s about the black body from the following is ____
(A) Emit or absorb energy in the form of electromagnetic radiation
(B) Frequency distribution of the emitted radiation depends on temperature
(C) At a given temperature, intensity vs frequency cur …

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :

Assertion A : In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes …

The number of correct statements from the following ______
A. For 1s orbital, the probability density is maximum at the nucleus.
B. For 2 s orbital, the probability density first increases to maximum and then decreases sharply to zero.
C. Boundary surface diagrams of the orbitals …

Values of work function $({\mathrm{W}}_0)$ for a few metals are given below

The number of metals which will show photoelec …

The energy of an electron in the first Bohr orbit of hydrogen atom is $-2.18\times 10^{-18}J$. Its energy in the third Bohr orbit is ______.

The orbital angular momentum of an electron in 3s orbital is $\frac{\mathrm{xh}}{2\pi }$. The value of x is ____.

Given below are two statements:

Statement I: According to Bohr's model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised.

Statement II : The concept of electron in Bohr's orbit, violates the Heisenberg uncertainty principle. In the l …

The total number of isoelectronic species from the given set is ____
${\mathrm{O}}^{2-},{\mathrm{F}}^{-},\mathrm{Al},{\mathrm{Mg}}^{2+},{\mathrm{Na}}^{+},{\mathrm{O}}^{+},\mathrm{Mg},{\mathrm{Al}}^{3+},\mathrm{F}$

Electrons in a cathode ray tube have been emitted with a velocity of $1000{\mathrm{ms}}^{-1}$. The number of following statements which is/are true about the emitted radiation is ____.

Given : …

It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power 'n' i.e. $v^{\mathrm{n}}$ of X-rays emitted is plotted against atomic number 'Z', following graph is obtained.

The value of 'n' is

If wavelength of the first line of the Paschen series of hydrogen atom is 720 nm, then the wavelength of the second line of this series is ______ nm.
(Nearest integer)

The number of s-electrons present in an ion with 55 protons in its unipositive state is

Following figure shows spectrum of an ideal black body at four different temperatures. The number of correct statement/s from the following is ____.

A. ${\mathrm{T}}_4>{\mathrm{T}}_3>{\mathrm{T}}_2>{\mathrm{T}}_1$
B. The black body consists of particles performing simple harmoni …

The radius of the $2^{\text{nd }}$ orbit of ${\mathrm{Li}}^{2+}$ is x. The expected radius of the $3^{\text{rd }}$ orbit of ${\mathrm{Be}}^{3+}$ is

The number of given orbitals which have electron density along the axis is ____

${\mathrm{p}}_{\mathrm{x}}$, ${\mathrm{p}}_{\mathrm{y}}$, ${\mathrm{p}}_{\mathrm{z}}$, ${\mathrm{d}}_{\mathrm{xy}}$, ${\mathrm{d}}_{\mathrm{yz}}$, ${\mathrm{d}}_{\mathrm{xz}}$, ${\mathrm{d}}_{{\mathrm{z}}^2}$, …

The shortest wavelength of hydrogen atom in Lyman series is $\lambda$. The longest wavelength in Balmer series of ${\mathrm{He}}^{+}$ is

Assume that the radius of the first Bohr orbit of hydrogen atom is $0.6\mathring{A}$. The radius of the third Bohr orbit of $\mathrm{He}{}^{+}$ is $\_\_\_\_$ picometer. (Nearest Integer)

The energy of one mole of photons of radiation of frequency $2\times 10^{12}\mathrm{Hz}$ in $\mathrm{J}{\mathrm{mol}}^{-1}$ is ______.
(Nearest integer)
(Given: $\mathrm{h}=6.626\times 10^{-34}\mathrm{Js}$ …

Which one of the following sets of ions represents a collection of isoelectronic species?
(Given : Atomic Number : F :9, Cl : 17, Na = 11, $\mathrm{Mg}=12,\mathrm{Al}=13,\mathrm{K}=19,\mathrm{Ca}=20,\mathrm{Sc}=21$)

Arrange the following orbitals in decreasing order of energy ?
(A) $\mathrm{n}=3,\mathrm{l}=0,\mathrm{m}=0$
(B) $\mathrm{n}=4,\mathrm{l}=0,\mathrm{m}=0$
(C) $\mathrm{n}=3,\mathrm{l}=1,\mathrm{m}=0$
(D) $\mathrm{n}=3,\mathrm{l}=2,\mathrm{m}=1$

The correct option for t …

Maximum number of electrons that can be accommodated in shell with $\mathrm{n}=4$ are:

The wave function $(\Psi )$ of 2 s is given by
${\Psi }_{2\mathrm{s}}=\frac{1}{2\sqrt{2\pi }}{\left(\frac{1}{{\mathrm{a}}_0}\right)}^{1/2}\left(2-\frac{\mathrm{r}}{{\mathrm{a}}_0}\right){\mathrm{e}}^{-\mathrm{r}/2{\mathrm{a}}_0}$
At $r=r_0$, radial node is formed. Thus, …

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n=4$ to $n=2$ of ${\mathrm{He}}^{+}$spectrum

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. …

Identify the incorrect statement from the following.
(A) A circular path around the nucleus in which an electron moves is proposed as Bohr's orbit.
(B) An orbital is the one electron wave function ($\Psi$) in an atom.
(C) The existence of Bohr's orbits is supported by hydrogen …