At temperature T , the average kinetic energy of any particle is 3 2 kT . The de Broglie wavelength follows the order:

Visible photon > thermal electron > thermal neutron.

Thermal neutron > visible photon > thermal electron.

Thermal neutron > thermal electron > visible photon.

Visible photon > thermal neutron > thermal electron.

EASY

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The degeneracy of hydrogen atom that has energy equal to $- \frac{R_{H}}{9}$ (where R_H is Rydberg constant) is

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Important Questions on Atomic Structure

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

At temperature

T

, the average kinetic energy of any particle is

\frac{3}{2} kT

. The de Broglie wavelength follows the order:

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Identify the incorrect statement from the following.

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Which of the following combination of statements is true regarding the interpretation of the atomic orbitals?

(A)

An electron in an orbital of high angular momentum stays away from the nucleus than an electron in the orbital of lower angular momentum.

(B)

For a given value of the principal quantum number, the size of the orbit is inversely proportional to the azimuthal quantum number.

(C)

According to wave mechanics, the ground state angular momentum is equal to

\frac{h}{2 π}

(D)

The plot of

ψ

r

for various azimuthal quantum numbers, shows peak shifting towards higher

r

value.

HARD

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The wave function,

ψ_{n, l, m_{l}}

is a mathematical function whose value depends upon spherical polar coordinates

(r, θ, ϕ)

of the electron and characterized by the quantum numbers

n, l

and

m_{l}

. Here

r

is distance from nucleus,

θ

is colatitude and

ϕ

is azimuth. In the mathematical functions given in the Table, Z is atomic number and

a_{o}

is Bohr radius.

Column – 1	Column – 2	Column – 3
(I) $1 s$ orbital	(i) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{3}{2}} e^{- (\frac{Zr}{e_{o}})}$	(P)
(II) $2 s$ orbital	(ii) One radial node	(Q) Probability density at nucleus $\propto \frac{1}{a_{o}^{3}}$
(III) $2 p_{z}$ orbital	(iii) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{5}{2}} {re}^{- (\frac{Zr}{2 a_{o}})} \cos θ$	(R) Probability density is maximum at nucleus
(IV) $3 d_{z}^{2}$ orbital	(iv) $x y$ -plane is a nodal plane	(S) Energy needed to excite an electron from $n = 2$ state to $n = 4$ state is $\frac{27}{32}$ times the energy needed to excite electron from $n = 2$ state to $n = 6$ state.

For hydrogen atom, what is the only CORRECT combination?

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The number of orbitals associated with quantum numbers

n = 5, m_{s} = + \frac{1}{2}

is:

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

A stream of electrons from a heat filament was passed between two charge plates kept at a potential difference

V esu

. If

e

and

m

are charge and mass of an electron, respectively, then the value of

\frac{h}{λ}

(where

λ

is wavelength associated with the electron wave) is given by:

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

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

$p_{x}, p_{y}, p_{z}, d_{xy}, d_{yz}, d_{xz}, d_{z}^{2}, d_{x^{2} - y^{2}}$

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The electrons are more likely to be found:
Question Image

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The order of ionization energy

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The number of the radial nodes for

4 s

and

3 p

orbitals are respectively

HARD

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The wave function,

ψ_{n, l, m_{l}}

is a mathematical function whose value depends upon spherical polar coordinates

(r, θ, ϕ)

of the electron and characterized by the quantum numbers

n, l

and

m_{l}

. Here

r

is the distance from the nucleus,

θ

is colatitude and

ϕ

is azimuth. In the mathematical functions given in the Table,

Z

is the atomic number and

a_{o}

is Bohr radius

Column 1	Column 2	Column 3
(I) $1 s$ orbital	(i) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{3}{2}} e^{- (\frac{Zr}{e_{o}})}$	(P)
(II) $2 s$ orbital	(ii) One radial node	(Q) Probability density at the nucleus $\propto \frac{1}{a_{o}^{3}}$ .
(III) $2 p_{z}$ orbital	(iii) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{5}{2}} {re}^{- (\frac{Zr}{2 a_{o}})} \cos θ$	(R) Probability density is maximum at the nucleus.
(IV) $3 d_{z}^{2}$ orbital	(iv) $xy$ -plane is a nodal plane	(S) Energy needed to excite an electron from $n = 2$ state to $n = 4$ state is $\frac{27}{32}$ times the energy needed to excite are electron from $n = 2$ state to $n = 6$ state.

For

{He}^{+}

ion, the only incorrect combination

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The angular momentum of electron in

d

-orbital is equal to

HARD

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The wave function,

ψ_{n, l, m_{l}}

is a mathematical function whose value depends upon spherical polar coordinates

(r, θ, ϕ)

of the electron and characterized by the quantum numbers

n, l

and

m_{l}

. Here

r

is the distance from the nucleus,

θ

is colatitude and

ϕ

is azimuth. In the mathematical functions given in the Table,

Z

is the atomic number and

a_{o}

is Bohr radius

Column 1	Column 2	Column 3
(I) $1 s$ orbital	(i) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{3}{2}} e^{- (\frac{Zr}{e_{o}})}$	(P)
(II) $2 s$ orbital	(ii) One radial node	(Q) Probability density at the nucleus $\propto \frac{1}{a_{o}^{3}}$ .
(III) $2 p_{z}$ orbital	(iii) $ψ_{n, l, m_{l}} \propto {(\frac{Z}{a_{o}})}^{\frac{5}{2}} {re}^{- (\frac{Zr}{2 a_{o}})} \cos θ$	(R) Probability density is maximum at the nucleus.
(IV) $3 d_{z}^{2}$ orbital	(iv) $xy$ -plane is a nodal plane	(S) Energy needed to excite an electron from $n = 2$ state to $n = 4$ state is $\frac{27}{32}$ times the energy needed to excite are electron from $n = 2$ state to $n = 6$ state.

For the given orbital in column 1, the only correct combination for any hydrogen-like species is

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The correct set of four quantum numbers for the valence electrons of rubidium atom

(Z = 37)

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

The quantum number of four electrons are given below:

I . n = 4, l = 2, m_{l} = - 2, m_{s} = - 1 / 2

I I . n = 3, l = 2, m_{l} = 1, m_{s} = + 1 / 2

I I I . n = 4, l = 1, m_{l} = 0, m_{s} = + 1 / 2

I V . n = 3, l = 1, m_{l} = 1, m_{s} = - 1 / 2

The correct order of their increasing energies will be:

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Which one of the following about an electron occupying the 1s orbital in a hydrogen atom is incorrect? (The Bohr radius is represented by

a_{0}

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Among the following, the energy of

2 s

orbital is lowest in:

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Consider the following pairs of electrons:

(A) (a) $n = 3, l = 1, m_{l} = 1, m_{s} = + \frac{1}{2}$
(b) $n = 3, l = 2, m_{l} = 1, m_{s} = + \frac{1}{2}$
(B) (a) $n = 3, l = 2, m_{l} = - 2, m_{s} = - \frac{1}{2}$
(b) $n = 3, l = 2, m_{l} = - 1, m_{s} = - \frac{1}{2}$
(C) (a) $n = 4, l = 2, m_{l} = 2, m_{s} = + \frac{1}{2}$
(b) $n = 3, l = 2, m_{l} = 2, m_{s} = + \frac{1}{2}$

The pairs of electrons present in degenerate orbitals is/are:

MEDIUM

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Which of the following pairs of

d -

orbitals will have the electron density along the axis?

EASY

Science>Chemistry>Atomic Structure>Electronic Configuration of Elements

Two electrons occupying the same orbital are distinguished by:

The degeneracy of hydrogen atom that has energy equal to - R H 9 (where RH is Rydberg constant) is

Important Questions on Atomic Structure

Learn and Prepare for any exam you want !

The degeneracy of hydrogen atom that has energy equal to $- \frac{R_{H}}{9}$ (where R_H is Rydberg constant) is