The transition in the hydrogen spectrum that would have the same wavelength as Balmer transition from n = 4 to n = 2 of He+ spectrum is - 1. ${\mathrm{n}}_{1}$ $=$ $3$ $\mathrm{to}$ ${\mathrm{n}}_{2}$ $=$ $4$ 2. ${\mathrm{n}}_{2}$  = 3 to n1 = 2 3. ${\mathrm{n}}_{2}$  = 3 to n1 = 1 4. ${\mathrm{n}}_{2}$  = 2 to n1 = 1

Subtopic:  Hydrogen Spectra |
64%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

2 ×108 atoms of carbon are arranged side by side. The radius of a carbon atom if the length of this arrangement is 2.4 cm would be

1. 7.0 x 10-11 m

2. 5.0 x 10-11 m

3. 8.0 x 10-11 m

4. 6.0 x 10-11 m

Subtopic:  Introduction of Atomic Structure |
71%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The diameter of a zinc atom is 2.6 Å. If zinc atoms are arranged side by side lengthwise, number of atoms present in a length of 1.6 cm would be:

 1 5.153 x 107 2 6.153 x 107 3 4.153 x 109 4 6.153 x 103
Subtopic:  Introduction of Atomic Structure |
77%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A certain particle carries 2.5 × 10–16 C of static electric charge. The number of electrons present in it would be:

 1 1460 2 1350 3 1560 4 1660

Subtopic:  Introduction of Atomic Structure |
75%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

In Rutherford's experiment, generally, the thin foil of heavy atoms like gold, platinum, etc. have been used to be bombarded by the α-particles.

If the thin foil of light atoms like aluminum etc. is used in Rutherford’s experiment, the difference that would be observed from the above results is :

1. The same results will be observed.

2. More deflection would be observed.

3. There will not be enough deflection.

4. None of the above.

Subtopic:  Introduction of Atomic Structure |
62%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Symbols ${}_{35}{}^{79}\mathrm{Br}$ and ${}^{79}Br$ can be written,
whereas symbols ${}_{79}{}^{35}\mathrm{Br}$ and ${}^{35}Br$ are not acceptable because:

 1 The general convention for representing an element along with its atomic number (A) and atomic mass (Z) is ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$ 2 The general convention for representing an element along with its atomic mass (A) and atomic number (Z) is ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$ 3 The general convention for representing an element along with its wavelength (A) and frequency (Z) is ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$ 4 The general convention for representing an element along with its isotopes (A) and atomic number (Z) is ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$
Subtopic:  Introduction of Atomic Structure |
81%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The correct arrangement of the following electromagnetic spectrum in the increasing order of frequency is:

69%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The work function for the Cesium atom is $$1.9~\mathrm{eV}.$$ The threshold frequency of the radiation is:

 1 $$4.59 \times10^{14}~s^{-1}$$ 2 $$8.59 \times10^{14}~s^{-1}$$ 3 $$5.59 \times10^{-14}~s^{-1}$$ 4 $$65.9 \times10^{14}~s^{-1}$$
Subtopic:  Photo Electric Effect |
73%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

When a photon with a wavelength of 150 pm strikes an atom, one of its inner bound electrons is ejected at a velocity of 1.5 × 107 m s–1 The energy with which it is bound to the nucleus would be:

1. 32.22 × 10–16 J

2. 12.22 × 10–16 J

3. 22.27 × 10–16 J

4. 31.22 × 10–16 J

Subtopic:  Photo Electric Effect |
70%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

If the position of the electron were measured with an accuracy of +0.002 nm, the uncertainty in the momentum of the electron would be:

1. 5.637 × 10–23 kg m s–1

2. 4.637 × 10–23 kg m s–1

3. 2.637 × 10–23 kg m s–1

4. 3.637 × 10–23 kg m s–1

Subtopic:  Heisenberg Uncertainty Principle |
72%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints