NEET > Structure of Atom

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


Q 1.    

Correct4

Incorrect-1

If {tex} n = 6 , {/tex} the correct sequence for filling of electrons will be

{tex} n s \rightarrow ( n - 2 ) f \rightarrow ( n - 1 ) d \rightarrow n p {/tex}

B

{tex} n s \rightarrow ( n - 1 ) d \rightarrow ( n - 2 ) f \rightarrow n p {/tex}

C

{tex} n s \rightarrow ( n - 2 ) f \rightarrow n p \rightarrow ( n - 1 ) d {/tex}

D

{tex} n s \rightarrow n p ( n - 1 ) d \rightarrow ( n - 2 ) f {/tex}

Explanation

Q 2.    

Correct4

Incorrect-1

According to the Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon?

A

{tex} n = 6 {/tex} to {tex} n = 1 {/tex}

B

{tex} n = 5 {/tex} to {tex} n = 4 {/tex}

{tex} n = 6 {/tex} to {tex} n = 5 {/tex}

D

{tex} n = 5 {/tex} to {tex} n = 3 {/tex}

Explanation

Q 3.    

Correct4

Incorrect-1

A 0.66 kg ball is moving with a speed of 100{tex}\ \mathrm { m } / \mathrm { s } {/tex} The associated wavelength will be {tex} \left( h = 6.6 \times 10 ^ { - 34 } \mathrm { J\ s } \right) {/tex}

A

{tex} 6.6 \times 10 ^ { - 32 } \mathrm { m } {/tex}

B

{tex} 6.6 \times 10 ^ { - 34 } \mathrm { m } {/tex}

{tex} 1.0 \times 10 ^ { - 35 } \mathrm { m } {/tex}

D

{tex} 1.0 \times 10 ^ { - 32 } \mathrm { m } {/tex}

Explanation

Q 4.    

Correct4

Incorrect-1

Maximum number of electrons in a subshell of an atom is determined by the following

A

{tex} 21 + 1 {/tex}

B

{tex} 4l - 2 {/tex}

C

2{tex} n ^ { 2 } {/tex}

{tex} 4l + 2 {/tex}

Explanation

Q 5.    

Correct4

Incorrect-1

Which of the following is not permissible arrangement of electrons in an atom?

A

{tex} n = 5 , l = 3 , m = 0 , s = + 1 / 2 {/tex}

{tex} n = 3 , l = 2 , m = - 3 , s = - 1 / 2 {/tex}

C

{tex} n = 3 , l = 2 , m = - 2 , s = - 1 / 2 {/tex}

D

{tex} n = 4 , l = 0 , m = 0 , s = - 1 / 2 {/tex}

Explanation

Q 6.    

Correct4

Incorrect-1

The measurement of the electron position is associated with an uncertainty in momentum, which is equal to {tex} 1 \times 10 ^ { - 18 } \mathrm { g }\ \mathrm { cm }\ \mathrm s^{-1}{/tex} . The uncertainty in electron velocity is (mass of an electron is {tex} \ 9 \times 10 ^ { - 28 } \mathrm { g }) {/tex}

A

{tex} 1 \times 10 ^ { 5 } \mathrm { cm } \ \mathrm { s } ^ { - 1 } {/tex}

B

{tex} 1 \times 10 ^ { 11 } \mathrm { cm } \ \mathrm { s } ^ { - 1 } {/tex}

{tex} 1 \times 10 ^ { 9 } \mathrm { cm } \ \mathrm { s } ^ { - 1 } {/tex}

D

{tex} 1 \times 10 ^ { 6 } \mathrm { cm }\ \mathrm { s } ^ { - 1 } {/tex}

Explanation

Q 7.    

Correct4

Incorrect-1

Consider the following sets of quantum numbers:
{tex} \begin{array} { l l l l } { } & { n } & { l } & { m } & { s } \\ { \text { (i) } } & { 3 } & { 0 } & { 0 } & { + 1 / 2 } \\ { \text { (ii) } } & { 2 } & { 2 } & { 1 } & { + 1 / 2 } \\ { \text { (iii) } } & { 4 } & { 3 } & { - 2 } & { - 1 / 2 } \\ { \text { (iv) } } & { 1 } & { 0 } & { - 1 } & { - 1 / 2 } \\ { \text { (v) } } & { 3 } & { 2 } & { 3 } & { + 1 / 2 } \end{array} {/tex}
Which of the following sets of quantum number is not possible?

A

(i), (ii), (iii) and (iv)

(ii), (iv) and (v)

C

(i) and (iii)

D

(ii), (iii) and (iv).

Explanation

Q 8.    

Correct4

Incorrect-1

The orientation of an atomic orbital is governed by

A

principal quantum number

B

azimuthal quantum number

C

spin quantum number

magnetic quantum number.

Explanation

Q 9.    

Correct4

Incorrect-1

The energy of second Bohr orbit of the hydrogen atom is {tex} - 328 \mathrm { kJ }\ \mathrm { mol } ^ { - 1 } ; {/tex} hence the energy of fourth Bohr orbit would be

A

{tex} - 41\ \mathrm { kJ }\ \mathrm { mol } ^ { - 1 } {/tex}

{tex} - 82 \ \mathrm { kJ }\ \mathrm { mol } ^ { - 1 } {/tex}

C

{tex} - 164 \ \mathrm { kJ }\ \mathrm { mol } ^ { - 1 } {/tex}

D

{tex} - 1312\ \mathrm { kJ\ mol } ^ { - 1 } {/tex}

Explanation

Q 10.    

Correct4

Incorrect-1

The frequency of radiation emitted when the electron falls from {tex} n = 4 {/tex} to {tex} n = 1 {/tex} in a hydrogen atom will be (Given ionization energy of {tex} \mathrm { H } = 2.18 \times 10 ^ { - 18 } \mathrm { J }\ \mathrm {atom} {/tex} {tex} ^ { - 1 } {/tex} and {tex} h = 6.625 \times 10 ^ { - 34 } \mathrm { J\ s } {/tex} )

A

{tex} 1.54 \times 10 ^ { 15 } \mathrm s ^ { - 1 } {/tex}

B

{tex} 1.03 \times 10 ^ { 15 } \mathrm { s } ^ { - 1 } {/tex}

{tex} 3.08 \times 10 ^ { 15 } \mathrm { s } ^ { - 1 } {/tex}

D

{tex} 2.00 \times 10 ^ { 15 } \mathrm { s } ^ { - 1 } {/tex}

Explanation

Q 11.    

Correct4

Incorrect-1

The following quantum numbers are possible for how many orbitals {tex} : n = 3 , l = 2 , m = + 2 ? {/tex}

1

B

2

C

3

D

4

Explanation

Q 12.    

Correct4

Incorrect-1

The uncertainty in momentum of an electron is {tex} 1 \times 10 ^ { - 5 } \mathrm { kg } \ \mathrm { m } / \mathrm { s } {/tex} . The uncertainty in its position will be {tex} \left( h = 6.62 \times 10 ^ { - 34 } \mathrm { kg }\ \mathrm { m } ^ { 2 } / \mathrm { s } \right) {/tex}

{tex} 5.27 \times 10 ^ { - 30 } \mathrm { m } {/tex}

B

{tex} 1.05 \times 10 ^ { - 26 }\ \mathrm { m } {/tex}

C

{tex} 1.05 \times 10 ^ { - 28 }\ \mathrm { m } {/tex}

D

{tex} 5.25 \times 10 ^ { - 28 }\ \mathrm { m } {/tex}

Explanation

Q 13.    

Correct4

Incorrect-1

Who modified Bohr's theory by introducing elliptical orbits for electron path?

A

Rutherford

B

Thomson

C

Hund

Sommerfield

Explanation

Q 14.    

Correct4

Incorrect-1

The de Broglie wavelength of a particle with mass 1{tex}\ \mathrm { g } {/tex} and velocity 100{tex}\ \mathrm { m } / \mathrm { s } {/tex} is

A

{tex} 6.63 \times 10 ^ { - 35 }\ \mathrm { m } {/tex}

B

{tex} 6.63 \times 10 ^ { - 34 }\ \mathrm { m } {/tex}

{tex} 6.63 \times 10 ^ { - 33 }\ \mathrm { m } {/tex}

D

{tex} 6.65 \times 10 ^ { - 35 }\ \mathrm { m } {/tex}

Explanation

Q 15.    

Correct4

Incorrect-1

The Bohr orbit radius for the hydrogen atom ({tex}n{/tex} = 1) is approximately 0.530 {tex} {\text{Å}}{/tex}. The radius for the first excited state (n = 2) orbit is (in {tex} {\text{Å}}{/tex} )

A

4.77

B

1.06

C

0.13

2.12

Explanation

Q 16.    

Correct4

Incorrect-1

The position of both, an electron and a helium atom is known within 1.0 nm. Further the momentum of the electron is known within {tex} 5.0 \times 10 ^ { - 26 }\ \mathrm { kg }\ \mathrm { m }\ \mathrm { s } ^ { - 1 } {/tex}. The minimum uncertainty in the measurement of the momentum of the helium atom is

A

{tex} 8.0 \times 10 ^ { - 26 }\ \mathrm { kg }\ \mathrm { m }\ \mathrm { s } ^ { - 1 } {/tex}

B

80{tex}\ \mathrm { kg }\ \mathrm { m\ s } ^ { - 1 } {/tex}

C

50{tex}\ \mathrm { kg }\ \mathrm { m } \ \mathrm { s } ^ { - 1 } {/tex}

{tex} 5.0 \times 10 ^ { - 26 }\ \mathrm { kg }\ \mathrm { m }\ \mathrm { s } ^ { - 1 } {/tex}

Explanation

Q 17.    

Correct4

Incorrect-1

What will be the longest wavelength line in Balmer series of spectrum?

A

546{tex} \mathrm { nm } {/tex}

656{tex} \mathrm { nm } {/tex}

C

566{tex} \mathrm { nm } {/tex}

D

556{tex} \mathrm { nm } {/tex}

Explanation

Q 18.    

Correct4

Incorrect-1

In a Bohr's model of an atom, when an electron jumps from {tex} n = 1 {/tex} to {tex} n = 3 , {/tex} how much energy will be emitted or absorbed?

A

{tex} 2.389 \times 10 ^ { - 12 } {/tex} ergs

B

{tex} 0.239 \times 10 ^ { - 10 } {/tex} ergs

C

{tex} 2.15 \times 10 ^ { - 11 } {/tex} ergs

{tex} 0.1936 \times 10 ^ { - 10 } {/tex} ergs

Explanation

Q 19.    

Correct4

Incorrect-1

Uncertainty in position of an electron (mass {tex} = 9.1 \times 10 ^ { - 28 }\ \mathrm { g } {/tex} ) moving with a velocity of {tex} 3 \times 10 ^ { 4 }\ \mathrm { cm } / \mathrm { s } {/tex} accurate upto 0.001{tex} \% {/tex} will be (Use {tex} h / ( 4 \pi ) {/tex} in uncertainty expression where {tex} h = 6.626 \times 10 ^ { - 27 } {/tex} erg second)

A

5.76{tex}\ \mathrm { cm } {/tex}

B

7.68{tex}\ \mathrm { cm } {/tex}

1.93{tex}\ \mathrm { cm } {/tex}

D

3.84{tex}\ \mathrm { cm } {/tex}

Explanation



Q 20.    

Correct4

Incorrect-1

For which of the following sets of four quantum numbers, an electron will have the highest energy?

A

{tex} \begin{array} { l l l l } { n } & { l } & { m } & { s } \\ { 3 } & { 2 } & { 1 } & { + 1 / 2 } \end{array} {/tex}

{tex} \begin{array} { l l l l } {4 } & { 2 } & {-1 } & { +1/2 } \end{array} {/tex}

C

{tex} \begin{array} { l l l l } {4 } & { 1 } & {0 } & { -1/2 } \end{array} {/tex}

D

{tex} \begin{array} { l l l l } {5 } & { 0 } & {0 } & { -1/2 } \end{array} {/tex}

Explanation

Q 21.    

Correct4

Incorrect-1

Which one of the following is not isoelectronic with {tex} \mathrm { O } ^ { 2 - } ? {/tex}

{tex} \mathrm { T } \mathrm { I } ^ { + } {/tex}

B

{tex} \mathrm { Na } ^ { + } {/tex}

C

{tex} \mathrm { N } ^ { 3 - } {/tex}

D

{tex} \mathrm {F^-} {/tex}

Explanation

Q 22.    

Correct4

Incorrect-1

Electronic configuration of calcium atom can be written as

A

{tex} [ \mathrm { Ne } ] \ 4 p ^ { 2 } {/tex}

{tex} [ \mathrm { Ar } ] \ 4 s ^ { 2 } {/tex}

C

{tex} [ \mathrm { Ne } ] \ 4 s ^ { 2 } {/tex}

D

{tex} [ \mathrm { Kr } ]\ 4 p ^ { 2 } {/tex}

Explanation

Q 23.    

Correct4

Incorrect-1

The energy of an electron in the {tex} n ^ { \text {th } } {/tex} Bohr orbit of hydrogen atom is

A

{tex} \frac { 13.6 } { n ^ { 4 } } \mathrm { eV } {/tex}

B

{tex} \frac { 13.6 } { n ^ { 3 } } \mathrm { eV } {/tex}

{tex} \frac { 13.6 } { n ^ { 2 } } \mathrm { eV } {/tex}

D

{tex} \frac { 13.6 } { n } \mathrm { eV } {/tex}

Explanation

Q 24.    

Correct4

Incorrect-1

In a given atom no two electrons can have the same values for all the four quantum numbers. This is called

A

Hund's Rule

B

Aufbau principle

C

Uncertainty principle

Pauli's Exclusion principle.

Explanation

Q 25.    

Correct4

Incorrect-1

The order of filling of electrons in the orbitals of an atom will be

A

{tex} 3 d , 4 s , 4 p , 4 d , 5 s {/tex}

{tex} 4 s , 3 d , 4 p , 5 s , 4 d {/tex}

C

{tex} 5 s , 4 p , 3 d , 4 d , 5 s {/tex}

D

{tex} 3 d , 4 p , 4 s , 4 d , 5 s {/tex}

Explanation