JEE Main > Structure of Atom

Explore popular questions from Structure of Atom for JEE Main. This collection covers Structure of Atom previous year JEE Main questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Uncertainty in position of a minute particle of mass 25{tex} \mathrm { g } {/tex} in space is {tex} 10 ^ { - 5 } \mathrm { m } {/tex} . What is the uncertainty in its velocity {tex} \left( \text { in } \mathrm { ms } ^ { - 1 } \right) ? {/tex}

A

{tex} 2.1 \times 10 ^ { - 34 } {/tex}

B

{tex} 0.5 \times 10 ^ { - 34 } {/tex}

{tex} 2.1 \times 10 ^ { - 28 } {/tex}

D

{tex} 0.5 \times 10 ^ { - 23 } {/tex}

Explanation



Q 2.    

Correct4

Incorrect-1

The number of d-electrons retained in {tex} \mathrm { Fe } ^ { 2 + } {/tex} (At. no of {tex} \mathrm { Fe } = 26 {/tex} ) ion is

A

4

B

5

6

D

3

Explanation

Q 3.    

Correct4

Incorrect-1

The orbital angular momentum for an electron revolving in an orbit is given by {tex} \sqrt { l ( l + 1 ) } \cdot \frac { \mathrm { h } } { 2 \pi } {/tex} . This momentum for an s-electron will be given by

Zero

B

{tex} \frac { h } { 2 \pi } {/tex}

C

{tex} \sqrt { 2 } \cdot \frac { \mathrm { h } } { 2 \pi } {/tex}

D

{tex} + \frac { 1 } { 2 } \cdot \frac { \mathrm { h } } { 2 \pi } {/tex}

Explanation

Q 4.    

Correct4

Incorrect-1

Which one of the following groupings represents a collection of isoelectronic species ?{tex} ( \text { At. nos.: } \mathrm { Cs } : 55 , {/tex} {tex} \mathrm { Br } : 35 ) {/tex}

{tex} \mathbf { N } ^ { 3 - } , \mathbf { F } ^ { - } , \mathbf { N a } ^ { + } {/tex}

B

{tex} \mathrm { Be } , \mathrm { Al } ^ { 3 + } , \mathrm { Cl } ^ { - } {/tex}

C

{tex} \mathrm { Ca } ^ { 2 + } , \mathrm { Cs } ^ { + } , \mathrm { Br } {/tex}

D

{tex} \mathrm { Na } ^ { + } , \mathrm { Ca } ^ { 2 + } , \mathrm { Mg } ^ { 2 + } {/tex}

Explanation

Q 5.    

Correct4

Incorrect-1

In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen

5{tex} \rightarrow 2 {/tex}

B

4{tex} \rightarrow 1 {/tex}

C

2{tex} \rightarrow 5 {/tex}

D

3{tex} \rightarrow 2 {/tex}

Explanation



Q 6.    

Correct4

Incorrect-1

The de Broglie wavelength of a tennis ball of mass {tex} 60\ \mathrm { g } {/tex} moving with a velocity of {tex} 10{/tex} metres per second is approximately

A

{tex} 10 ^ { - 31 } {/tex} metres

B

{tex} 10 ^ { - 16 } {/tex} metres

C

{tex} 10 ^ { - 25 } {/tex} metres

{tex} 10 ^ { - 33 } {/tex} metres

Explanation

Q 7.    

Correct4

Incorrect-1

Which of the following sets of quantum numbers is correct for an electron in 4f orbital?

{tex} \mathrm { n } = 4 , \ell = 3 , \mathrm { m } = + 1 , \mathrm { s } = + 1 / 2 {/tex}

B

{tex} \mathrm { n } = 4 , \ell = 4 , \mathrm { m } = - 4 , \mathrm { s } = - 1 / 2 {/tex}

C

{tex} \mathrm { n } = 4 , \ell = 3 , \mathrm { m } = + 4 , \mathrm { s } = + 1 / 2 {/tex}

D

{tex} \mathrm { n } = 3 , \ell = 2 , \mathrm { m } = - 2 , \mathrm { s } = + 1 / 2 {/tex}

Explanation





Q 8.    

Correct4

Incorrect-1

Consider the ground state of {tex} \mathrm Cr{/tex} atom {tex} ( \mathrm { X } = 24 ) {/tex} . The number of electrons with the azimuthal quantum numbers, {tex} \ell = 1 {/tex} and 2 are, respectively

A

16 and 4

12 and 5

C

12 and 4

D

16 and 5

Explanation



Q 9.    

Correct4

Incorrect-1

The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state {tex} 1 , {/tex} would
{tex} \left.\text { be (Rydberg constant } = 1.097 \times 10 ^ { 7 } \mathrm { m } ^ { - 1 } \right) {/tex}

A

{tex}406\ \mathrm { nm } {/tex}

B

{tex} 192\ \mathrm { nm } {/tex}

{tex} 91\ \mathrm { nm } {/tex}

D

{tex} 9.1 \times 10 ^ { - 8 } \mathrm { nm } {/tex}

Explanation



Q 10.    

Correct4

Incorrect-1

Which one of the following sets of ions represents the collection of isoelectronic species?

A

{tex} \mathrm { K } ^ { + } , \mathrm { Cl } ^ { - } , \mathrm { Mg } ^ { 2 + } , \mathrm { Sc } ^ { 3 + } {/tex}

B

{tex} \mathrm { Na } ^ { + } , \mathrm { Ca } ^ { 2 + } , \mathrm { Sc } ^ { 3 + } , \mathrm { F } ^ { - } {/tex}

{tex} \mathrm { K } ^ { + } , \mathrm { Ca } ^ { 2 + } , \mathrm { Sc } ^ { 3 + } , \mathrm { Cl } ^ { - } {/tex}

D

{tex} \mathrm { Na } ^ { + } , \mathrm { Mg } ^ { 2 + } , \mathrm { Al } ^ { 3 + } , \mathrm { Cl } ^ { - } {/tex}

Explanation

Q 11.    

Correct4

Incorrect-1

In a multi-electron atom, which of the following orbitals described by the three quantum members will have the same energy in the absence of magnetic and electric fields?
{tex} \begin{array} { l l } { \text { (A) } n = 1 , l = 0 , m = 0 } & { \text { (B) } n = 2 , l = 0 , m = 0 } \\ { \text { (C) } n = 2 , l = 1 , m = 1 } & { \text { (D) } n = 3 , l = 2 , m = 1 } \\ { \text { (E) } n = 3 , l = 2 , m = 0 } \end{array} {/tex}

(D) and (E)

B

(C) and (D)

C

(B) and (C)

D

(A) and (B)

Explanation

Q 12.    

Correct4

Incorrect-1

Of the following sets which one does NOT contain isoelectronic species?

A

{tex} \mathrm { BO } _ { 3 } ^ { 3 - } , \mathrm { CO } _ { 3 } ^ { 2 - } , \mathrm { NO } _ { 3 } ^ { - } {/tex}

{tex} \mathrm { SO } _ { 3 } ^ { 2 - } , \mathrm { CO } _ { 3 } ^ { 2 - } , \mathrm { NO } _ { 3 } ^ { - } {/tex}

C

{tex} \mathrm { CN } ^ { - } , \mathrm { N } _ { 2 } , \mathrm { C } _ { 2 } ^ { 2 - } {/tex}

D

{tex} \mathrm { PO } _ { 4 } ^ { 3 - } , \mathrm { SO } _ { 4 } ^ { 2 - } , \mathrm { ClO } _ { 4 } ^ { - } {/tex}

Explanation









Q 13.    

Correct4

Incorrect-1

According to Bohr's theory, the angular momentum of an electron in {tex} 5 ^ { \text {th } } {/tex} orbit is

A

{tex}10\ \mathrm { h } / \pi {/tex}

{tex}2.5\ \mathrm { h } / \pi {/tex}

C

{tex}25\ \mathrm { h } / \pi {/tex}

D

{tex}1.0\ \mathrm { h } / \pi {/tex}

Explanation





Q 14.    

Correct4

Incorrect-1

Uncertainty in the position of an electron (mass {tex} = 9.1 \times {/tex} {tex} 10 ^ { - 31 } \mathrm { kg } {/tex} ) moving with a velocity {tex} 300\ \mathrm { ms } ^ { - 1 } , {/tex} accurate upto {tex} 0.001\ \% {/tex} will be
{tex} \left( h = 6.63 \times 10 ^ { - 34 } \mathrm { Js } \right) {/tex}

{tex} 1.92 \times 10 ^ { - 2 } \mathrm { m } {/tex}

B

{tex} 3.84 \times 10 ^ { - 2 } \mathrm { m } {/tex}

C

{tex} 19.2 \times 10 ^ { - 2 } \mathrm { m } {/tex}

D

{tex} 5.76 \times 10 ^ { - 2 } \mathrm { m } {/tex}

Explanation



Q 15.    

Correct4

Incorrect-1

Which one of the following sets of ions represents a collection of isoelectronic species?

A

{tex} \mathrm { N } ^ { 3 - } , \mathrm { O } ^ { 2 - } , \mathrm { F } ^ { - } , \mathrm { S } ^ { 2 - } {/tex}

B

{tex} \mathrm { Li } ^ { + } , \mathrm { Na } ^ { + } , \mathrm { Mg } ^ { 2 + } , \mathrm { Ca } ^ { 2 + } {/tex}

{tex} \mathrm { K } ^ { + } , \mathrm { Cl } ^ { - } , \mathrm { Ca } ^ { 2 + } , \mathrm { Sc } ^ { 3 + } {/tex}

D

{tex} \mathrm { Ba } ^ { 2 + } , \mathrm { Sr } ^ { 2 + } , \mathrm { K } ^ { + } , \mathrm { Ca } ^ { 2 + } {/tex}

Explanation







Q 16.    

Correct4

Incorrect-1

Which of the following sets of quantum numbers represents the highest energy of an atom?

A

{tex} \mathrm { n } = 3,l = 0 , \mathrm { m } = 0 , \mathrm { s } = + 1 / 2 {/tex}

B

{tex} \mathrm { n } = 3,l = 1 , \mathrm { m } = 1 , \mathrm { s } = + 1 / 2 {/tex}

{tex} \mathrm { n } = 3,l = 2 , \mathrm { m } = 1 , \mathrm { s } = + 1 / 2 {/tex}

D

{tex} \mathrm { n } = 4,l = 0 , \mathrm { m } = 0 , \mathrm { s } = + 1 / 2 {/tex}

Explanation







Q 17.    

Correct4

Incorrect-1

Which one of the following constitutes a group of the isoelectronic species?

A

{tex} \mathrm { C } _ { 2 } ^ { 2 - } , \mathrm { O } _ { 2 } ^ { - } , \mathrm { CO } , \mathrm { NO } {/tex}

{tex} \mathrm { NO } ^ { + } , \mathrm { C } _ { 2 } ^ { 2 - } , \mathrm { CN } ^ { - } , \mathrm { N } _ { 2 } {/tex}

C

{tex} \mathrm { CN } ^ { - } , \mathrm { N } _ { 2 } , \mathrm { O } _ { 2 } ^ { 2 - } , \mathrm { C } _ { 2 } ^ { 2 - } {/tex}

D

{tex} \mathrm { N } _ { 2 } , \mathrm { O } _ { 2 } ^ { - } , \mathrm { NO } ^ { + } , \mathrm { CO } {/tex}

Explanation





Q 18.    

Correct4

Incorrect-1

The ionization enthalpy of hydrogen atom is {tex} 1.312 \times 10 ^ { 6 } \mathrm { J } {/tex} {tex} \mathrm { mol } ^ { - 1 } . {/tex} The energy required to excite the electron in the atom from {tex} \mathrm { n } = 1 {/tex} to {tex} \mathrm { n } = 2 {/tex} is

A

{tex} 8.51 \times 10 ^ { 5 } \mathrm { J } \mathrm { mol } ^ { - 1 } {/tex}

B

{tex} 6.56 \times 10 ^ { 5 } \mathrm { Jmol } ^ { - 1 } {/tex}

C

{tex} 7.56 \times 10 ^ { 5 } \mathrm { J } \mathrm { mol } ^ { - 1 } {/tex}

{tex} 9.84 \times 10 ^ { 5 } \mathrm { J \ mol } ^ { - 1 } {/tex}

Explanation





Q 19.    

Correct4

Incorrect-1

Calculate the wavelength (in nanometer) associated with a proton moving at {tex} 1.0 \times 10 ^ { 3 } \mathrm { ms } ^ { - 1 } {/tex} .
{tex} \left.\text { (Mass of proton } = 1.67 \times 10 ^ { - 27 } \mathrm { kg } \text { and } \mathrm { h } = 6.63 \times 10 ^ { - 34 } \mathrm { Js } \right) {/tex}

{tex}0.40 \mathrm { \ nm } {/tex}

B

{tex}2.5 \mathrm {\ nm } {/tex}

C

{tex}14.0 \mathrm {\ nm } {/tex}

D

{tex}0.32 \mathrm {\ nm } {/tex}

Explanation

Q 20.    

Correct4

Incorrect-1

In an atom, an electron is moving with a speed of {tex} 600\,\ \mathrm { m } / \mathrm { s } {/tex} with an accuracy of {tex}0.005 \% {/tex} . Certainity with which the
position of the electron can be located is {tex} ( \mathrm { h } = 6.6 \times 10 ^ { - 34 } \mathrm { kg }{/tex} .{tex} \mathrm { m } ^ { 2 } \mathrm { s } ^ { - 1 } , \text { mass of electron, } \mathrm { e } _ { \mathrm { m } } = 9.1 \times 10 ^ { - 31 } \mathrm { kg )} {/tex} :

A

{tex} 5.10 \times 10 ^ { - 3 } \mathrm { m } {/tex}

{tex} 1.92 \times 10 ^ { - 3 } \mathrm { m } {/tex}

C

{tex} 3.84 \times 10 ^ { - 3 } \mathrm { m } {/tex}

D

{tex} 1.52 \times 10 ^ { - 4 } \mathrm { m } {/tex}

Explanation



Q 21.    

Correct4

Incorrect-1

The energy required to break one mole of {tex} \mathrm { Cl } - \mathrm { Cl } {/tex} bonds in {tex} \mathrm { Cl } _ { 2 } {/tex} is {tex}242\ \mathrm { kJ } \mathrm { mol } ^ { - 1 } {/tex} . The longest wavelength of light capable of breaking a single {tex} \mathrm { Cl } - \mathrm { Cl } {/tex} bond is
{tex} \left( c = 3 \times 10 ^ { 8 } \mathrm { ms } ^ { - 1 } \text { and } N _ { A } = 6.02 \times 10 ^ { 23 } \mathrm { mol } ^ { - 1 } \right) {/tex}

A

{tex}594 \mathrm { nm } {/tex}

B

{tex}640 \mathrm { nm } {/tex}

C

{tex}700 \mathrm { nm } {/tex}

{tex} 494\mathrm { nm } {/tex}

Explanation





Q 22.    

Correct4

Incorrect-1

Ionisation energy of {tex} \mathrm { He } ^ { + } {/tex} is {tex} 19.6 \times 10 ^ { - 18 } \mathrm { J } {/tex} atom {tex} ^ { - 1 } . {/tex} The energy of the first stationary state {tex} ( n = 1 ) {/tex} of {tex} \mathrm { Li } ^ { 2 + } {/tex} is

A

{tex} 4.41 \times 10 ^ { - 16 } \mathrm { J } {/tex} atom {tex} ^ { - 1 } {/tex}

{tex} - 4.41 \times 10 ^ { - 17 } \mathrm { J\ atom } ^ { - 1 } {/tex}

C

{tex} - 2.2 \times 10 ^ { - 15 } \mathrm { J } {/tex} atom {tex} ^ { - 1 } {/tex}

D

{tex} 8.82 \times 10 ^ { - 17 } \mathrm { J } \mathrm { atom } ^ { - 1 } {/tex}

Explanation









Q 23.    

Correct4

Incorrect-1

A gas absorbs a photon of 355{tex} \mathrm { nm } {/tex} and emits at two wavelengths. If one of the emissions is at {tex} 680\ \mathrm { nm } {/tex} , the other is at:

A

{tex}1035\ \mathrm { nm } {/tex}

B

{tex}325\ \mathrm { nm } {/tex}

{tex} 743\ \mathrm { nm } {/tex}

D

{tex} 518\ \mathrm { nm } {/tex}

Explanation









Q 24.    

Correct4

Incorrect-1

The electrons identified by quantum numbers {tex} n {/tex} and {tex} \ell : {/tex}
{tex} \begin{array} { l l } { \text { (A) } n = 4 , \ell = 1 } & { \text { (B) } n = 4 , \ell = 0 } \\ { \text { (C) } n = 3 , \ell = 2 } & { \text { (D) } n = 3 , \ell = 1 } \end{array} {/tex}
can be placed in order of increasing energy as:

A

{tex} ( C ) < ( D ) < ( B ) < ( A ) {/tex}

{tex} ( D ) < ( B ) < ( C ) < ( A ) {/tex}

C

{tex} ( B ) < ( D ) < ( A ) < ( C ) {/tex}

D

{tex} ( A ) < ( C ) < ( B ) < ( D ) {/tex}

Explanation





Q 25.    

Correct4

Incorrect-1

Energy of an electron is given by {tex} \mathrm { E } = - 2.178 \times 10 ^ { - 18 } \mathrm { J } \left( \frac { Z ^ { 2 } } { n ^ { 2 } } \right) {/tex}
Wavelength of light required to excite an electron in an hydrogen atom from level {tex} n = 1 {/tex} to {tex} n = 2 {/tex} will be :
{tex} \left( \mathrm { h } = 6.62 \times 10 ^ { - 34 } \mathrm { J } \mathrm { s } \text { and } \mathrm { c } = 3.0 \times 10 ^ { 8 } \mathrm { ms } ^ { - 1 } \right) {/tex}

{tex} 1.214 \times 10 ^ { - 7 } \mathrm { m } {/tex}

B

{tex} 2.816 \times 10 ^ { - 7 } \mathrm { m } {/tex}

C

{tex}6.500 \times 10 ^ { - 7 } \mathrm { m } {/tex}

D

{tex} 8.500 \times 10 ^ { - 7 } \mathrm { m } {/tex}

Explanation