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

Earn 100

Number of orbital(s) in zinc having at least one angular node:

50% studentsanswered this correctly

Important Questions on Structure of Atom

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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:

HARD

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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?

HARD

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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}

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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

(Z = 37)

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

Among the following, the energy of

2 s

orbital is lowest in:

HARD

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The de Broglie wavelength of an electron in the

4^{t h}

Bohr's orbit of hydrogen is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The angular momentum of electron in

d

-orbital is equal to

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

Which of the following pairs of

d -

orbitals will have the electron density along the axis?

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The graph between

{|ψ|}^{2}

and

r

(radical distance) is shown below. This represents:
Question Image

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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.

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

What is the maximum number of orbitals that can be identified with the following quantum number

n = 3, l = 1, m = 0

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The electrons are more likely to be found:
Question Image

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The number of orbitals associated with quantum numbers

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

is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

The number of subshells associated with

n = 4

and

m = - 2

quantum numbers is:

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

Two particles

A

and

B

are in motion. If the wavelength associated with

A

33.33 nm

, the wavelength associated with

B

whose momentum is

\frac{1}{3} rd

A

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

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

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

At temperature

T

, the average kinetic energy of any particle is

\frac{3}{2} kT

. The de Broglie wavelength follows the order:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Quantum Mechanical Model of the Atom

Two electrons occupying the same orbital are distinguished by:

Number of orbital(s) in zinc having at least one angular node:

Important Questions on Structure of Atom

Learn and Prepare for any exam you want !