Atomic Structure- NEET Previous Year Questions with Solutions and Weightage

In NEET Chemistry section, Quantum Numbers, Electron Configuration are the most important and most asked topics from the Atomic Structure chapter. Atomic Structure generally carries around 6% weightage with 2-3 questions in the NEET UG Chemistry section. This accounts for approximately 8-12 marks out of the total 180 marks allocated for Chemistry.

The NEET Chemistry section consists of 45 questions. Each correct answer earns +4 marks, and each incorrect answer results in -1 mark.

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Most important and frequently asked questions from Atomic Structure in NEET UG Chemistry with detailed solutions are given below.

Question 1.

The decreasing order of atomic radii (pm) of Li,Be,B,C is: [NEET 2024]

1. Be > Li > B > C
2. Li > Be > B > C
3. C > B > Be > Li
4. Li > C > Be > B

View Solution

Question 2:

4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is [NEET UG 2019]:

1. 5f > 6p > 5p > 4d

2. 6p > 5f > 5p > 4d

3. 6p > 5f > 4d > 5p
4. 5f > 6p > 4d > 5p

View Solution

Question 3:

Calculate the energy in joule corresponding to light of wavelength 45 nm:

(Planck’s constant h = 6.63 × 10-34 Js; speed of light c = 3 × 108 ms-1) [NEET UG 2014]

1. 6.67 × 10¹¹
2. 4.42 × 10⁻¹⁵
3. 4.42 × 10⁻¹⁸
4. 6.67 × 10¹⁵

View Solution

Question 4:

What is the maximum number of orbitals that can be identified with the following quantum number? n = 3, l = 1, ml = 0 [NEET UG 2014]

1. 2

2. 3
3. 4
4. 1

View Solution

Question 5:

Be2+ is isoelectronic with which of the following ions? [NEET UG 2014]

1. Li+
2. Na+
3. Mg2+
4. H+

View Solution

Question 6:

Select the correct statements from the following :

A. Atoms of all elements are composed of two fundamental particles.

B. The mass of the electron is 9.10939 x 10-31 kg.

C. All the isotopes of a given element same chemical properties.

D. Protons and electrons are collected known as nucleons.

E. Dalton’s atomic theory, regarded atom as an ultimate particle of matter.

Choose the correct answer from the options given below : [NEET-UG 2023]

1. C, D and E only
2. A and E only
3. B, C and E only
4. A, B and C only

View Solution

Question 7:

Which of the following statements is not correct about diborane? [NEET 2022]

1. There are two 3-centre-2-electron bonds.
2. The four terminal B-H bonds are two centre two electron bonds.
3. The four terminal Hydrogen atoms and the two Boron atoms lie in one plane.
4. Both the Boron atoms are sp2 hybridised.

View Solution

Question 8:

In hydrogen atom, the de Broglie wavelength of an electron in the second Bohr orbit is : [Given that Bohr radius, a0 = 52.9pm] [NEET 2019]

1. 211.6pm

2. 211.6πpm
3. 52.9πpm
4. 105.8pm

View Solution

Question 9:

Which one is a wrong statement ? [NEET 2018]

1. The value of m for Dz2 is zero
2. Total orbital angular momentum of electron in ???
3. 
4. An orbital is designated by three quantum numbers while an electron in an atom is designated by four quantum numbers.

View Solution

Question 10:

Which one is the wrong statement ? [NEET 2017]

1. The uncertainty principle is \( \Delta E \times \Delta t \geq \frac{h}{4\pi} \)
2. Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement
3. The energy of 2s orbital is less than the energy of 2p orbital in case of Hydrogen like atoms
4. de-Broglie's wavelength is given by \( \lambda = \frac{h}{mv} \), where \( m \) = mass of the particle, \( v \) = group velocity of the particle.

View Solution

Question 11:

How many electrons can fit in the orbital for which n=3 and l=1 ?

[NEET (UG) - 2016]

1. 2
2. 6
3. 10
4. 14

View Solution

Question 12:

Which of the following pairs of d-orbitals will have electron density along the axes? [NEET 2014]

1. dz2, dxz
2. dxz, dyz
3. dz2 , dx2 - dy2
4. dxy , dx2 - dy2

View Solution

Question 13:

The total number of atomic orbitals in fourth energy level of an atom is : [NEET 2011]

1. 4
2. 8
3. 16
4. 32

View Solution

Question 14:

Consider the following sets of quantum number:

Which of the following sets of quantum number is not possible:

[NEET (UG) - 2007]

1. (ii), (iii) and (iv)
2. (i), (ii),(iii) and (iv)
3. (ii), (iv) and (v)
4. (i) and (iii)

View Solution

Question 15:

Mn and Mp represet the mass of neutron and proton respectively. An element having mass M has N neutron and Z-protons, then the correct relation will be [NEET UG 2001]

1. M < {N.Mn + Z.Mp}M < {N.Mn + Z.Mp}

2. M > {N.Mn + Z.Mp}
3. M = {N.Mn+Z.Mp}
4. M=N{Mn + Mp}

View Solution

Question 16:

Which rays contain (+ Ve) charged particle

[NEET (UG) - 2001]

1. α-rays
2. β-rays
3. γ-rays
4. X-rays

View Solution

Question 17:

Which of the following is never true for cathode rays?

[NEET (UG) - 1994]

1. They possess kinetic energy
2. They are electromagnetic waves
3. They produce heat
4. They produce mechanical pressure

View Solution

NEET Chemistry Paper Pattern

​The National Testing Agency (NTA) has revised the NEET UG 2025 exam pattern, reverting to the pre-COVID format. The NEET UG 2025 Chemistry section is structured to assess both theoretical knowledge and application-based understanding. Below is the detailed paper pattern for Chemistry in NEET 2025:

• Total Questions: 45
• Total Marks: 180
• Question Type: Multiple Choice Questions (MCQs)
• Marking Scheme:
  • +4 marks for each correct answer
  • -1 mark for each incorrect answer
  • 0 marks for unanswered questions

Chapter-Wise Distribution and Weightage Analysis

The Chemistry part of NEET UG 2025 has a total of 45 questions for 180 marks. It is further divided into three important branches: Physical Chemistry, Inorganic Chemistry, and Organic Chemistry. Each branch will approximately be 30-35% of the total Chemistry section.

Physical Chemistry includes questions that provide numerical problems. Inorganic Chemistry generally consists only of concepts with a huge part of it being memorization. Organic Chemistry is simply based on reaction mechanisms, named reactions, and perfect conceptualization.

NCERT is the main textbook that all students should focus on. Students should make sure to focus primarily on the fundamental concepts, practice numerical problems, and take mock tests as often as they can to build speed and accuracy. Students should consistently be reading, especially on theoretical topics like Chemical Bonding, Periodic Trends, and Coordination Compounds.

Detailed Topic-Wise Weightage for Chemistry in NEET UG 2025

Physical Chemistry (Class 11)

Physical Chemistry (Class 12)

Inorganic Chemistry (Class 11)

Inorganic Chemistry (Class 12)

Organic Chemistry (Class 11)

Organic Chemistry (Class 12)

NEET Question Paper 2024 PDF with Answer Key and Solution

NEET 2024 Question Paper PDF Code R

NEET 2024 Question Paper PDF Code Q

NEET 2024 Question Paper PDF Code T

NEET 2024 Question Paper PDF Code S

NEET Question Paper 2023 PDF Download with Solution

Here are NEET 2023 question paper of all the sets:

NEET Question Paper 2023 Set E

NEET 2023 Question Paper Set F

Question paper pdfs for F1, F2, F3, F4, F5, and F6 are available for download.

NEET 2023 Question Paper Set G

Question paper pdfs for G1, G2, G3, G4, G5, and G6 are available for download.

NEET 2023 Question Paper Set H

Question paper pdfs for H1, H2, H3, H4, H5, and H6 are available for download.

NEET Manipur Question Paper 2023 PDF Download

NEET Question Paper 2023 PDF Download in Hindi

NEET Question Paper 2022 in English

NEET 2022 Question Paper PDF for all paper codes is available for download.

NEET Question Paper 2022 Set Q

NEET 2022 question paper pdfs for Q1, Q2, Q3, Q4, Q5, and Q6 are available for download.

NEET Question Paper 2022 Set R

NEET Question Paper 2022 Set S

NEET Question Paper 2022 Set T

NEET Question Paper 2021 in English

It was for the first time in 2021 that NTA conducted NEET in 13 languages. Given below are the links to download question paper with solutions PDF in all the 13 languages for all paper codes.

NEET Question Paper 2021 Set M

NEET Question Paper 2021 Set N

NEET Question Paper 2021 Set O

NEET Question Paper 2021 Set P

NEET Question Paper 2020 in English- Set E, F, G, H

NEET Question Paper 2019

Frequently Asked Questions

Q1. What is the weightage of Atomic Structure in NEET?

Answer. Atomic Structure is a chapter worth about 4-6% in NEET UG Chemistry with 2-3 questions in the chapter for a total of 8-12 marks. Questions of topic Bohr’s Model, Quantum Numbers, De Broglie's equation, and the Photoelectric Effect have been frequently asked, making the chapter a must study in order to do well on the exam.

Q2. Is Atomic Structure important for NEET?

Answer: Certainly, Atomic Structure is a significant chapter for NEET UG. It is important to understand the theory and the numerical aspects of this chapter. A good understanding of this chapter can improve your Chemistry score overall.

Q3. Is Atomic Structure a tough chapter for NEET?

Answer: Atomic Structure is generally considered a chapter with moderate difficulty for NEET UG. There are more straightforward concepts such as Bohr’s Model and Quanta and Quantum Numbers, and a few others that can be slightly more challenging, such as Wave-Particle duality, Heisenberg’s uncertainty principle, and Energy Calculations. These topics may test your understanding more reliance on practice and several descriptors may show up for the examination. However, generally with consistent revision, focus on NCERT concepts, and continue practicing numerical problems, its possible to manage and perform effectively scoring chapter for NEET aspirants.

Q4. Which topic has more weightage in NEET?

Answer. In NEET UG Chemistry, some chapters carry higher weightage and are crucial for scoring well. The following topics are known to have high weightage and frequently appear in the exam:

Top High-Weightage Topics in NEET Chemistry

1. Equilibrium (Physical Chemistry)
2. Thermodynamics (Physical Chemistry)
3. Chemical Bonding and Molecular Structure (Inorganic Chemistry)
4. Coordination Compounds (Inorganic Chemistry)
5. Organic Chemistry - General Principles and Hydrocarbons (Organic Chemistry)
6. Aldehydes, Ketones, and Carboxylic Acids (Organic Chemistry)
7. Biomolecules and Polymers (Organic Chemistry)

Q5. What are Quantum numbers for NEET?

Answer. Quantum numbers describe the position and energy of electrons in an atom:

1. Principal Quantum Number (n): Defines the energy level (n = 1, 2, 3...).
2. Azimuthal Quantum Number (l): Defines the subshell and shape (l = 0 → s, 1 → p, 2 → d, 3 → f).
3. Magnetic Quantum Number (ml_ll​): Defines the orientation of orbitals (mll = -l to +l).
4. Spin Quantum Number (mss​): Defines the spin of electrons (+½ or -½).

These numbers collectively describe an electron’s complete address in an atom.

Q6. How to solve the quantum number question?

Answer. To solve quantum number questions in NEET:

1. Start with the energy level, which is defined by the Principal Quantum Number (n).
2. Calculate the Azimuthal Quantum Number (l), which must fall between 0 and (n-1).
3. Determine the Magnetic Quantum Number (mll), which varies between -l and +l.
4. If the spin quantum number (mss) is +½ or -½, check it.

Follow Pauli’s Exclusion Principle, Hund’s Rule, and Aufbau Principle to validate the values.