Effortless Way To Learn Atoms: 12th Physics, covering all your tackles!

4 min readJun 28, 2022

A fundamental part of class 12th physics is atoms, and by fundamental, I mean easy to understand.

A book by John Dalton (1766–1844) published in 1808, Atoms and All Things, advanced the concept that everything in the universe is made up of atoms. This has made him known as the “Father” of atomic theory. With DoubtConnect, you’ll have access to the tools, tips, and tricks you’ll need to navigate this chapter with ease.

So, What is an Atom?

It is a fact that the number of negative and positive charges in an atom is the same. As described by Thomson, atoms are composed of positive charges and electrons embedded within a sphere. The nucleus of Rutherford’s model has most of the atom’s mass, along with the positive charges associated with it, and the electrons revolve around it. Rutherford’s model failed to account for two explanations.

  • According to it, atoms are unstable because electrons may spiral into the nucleus as they revolve around the nucleus. It cannot be reconciled with the stability of matter.
  • The theory cannot explain the spectral properties of an atom line. Various elements have their own unique spectra that are stable. It consists of a line spectrum, which is an isolated parallel line.

Rutherford’s model is electromagnetically unstable, while Thomson’s has an electrostatic defect.

The hydrogen atom’s line spectrum

Each hydrogen atom consists of multiple series of line spectrums characterized as follows:

· Pfund Series

· Brackett Series

· Paschen Series

· Balmer Series

· Lyman Series

A Bohr atomic model postulates.

Quantum mechanics was founded by Niels Bohr, who laid the following foundations:

· The electrons of hydrogen atoms revolve around in stable orbits without releasing any radiant energy.

· There are only a few fixed values of the radius of an electron’s orbit that will produce an angular momentum that is an integral multiple of h/2 π, h being Planck’s constant.

· Whenever an electron transitions from a non-radiating orbit to one with lower energy, a photon is released that has the same energy as the difference between the two states. A photon’s frequency can then be calculated using v=hE−E.

How can you explain De Broglie’s Hypothesis?

According to this, electrons have a wavelength of

λ= h/mv

The number of wavelengths corresponding to each orbit circumference the main orbit corresponds to the number of circular standing waves.

Listed below are tips, tricks, and links to videos that can help you understand the chapter quickly and thoroughly:

A. Exam tips to follow

1. Attempt ALL NCERT questions, both those that are solved and those that are unsolved, as most of the CBSE exams are based on NCERT.

2. When reading the first chapter, do not worry about memorizing anything, just concentrate on understanding it.

3. Separate your quick revision lists into three categories: formulae, derivations, and definitions.

4. Know how each concept is applied. Clarify any doubts you may have with DoubtConnect. Write about what you have learned once you have understood the concepts.

5. Make sure you practice both theory and numerical questions.

B. Memorization tricks for long-term retention

1. During your exam, practice writing point-wise questions to improve your scores.

2. Practice papers from the past 10 years.

3. Your speed will improve if you complete the papers within the time you will have available on the day of the examination.

4. You should begin by revising a topic you are comfortable with. As a result, you will be able to study difficult topics with more stamina.

C. Links to better elucidate concepts

1. Atoms Class 12 Physics One-Shot- Sachin Sir (YouTube)

2. CBSE Class 12 Physics Atoms- Shiksha House (YouTube)

Learning from videos is always helpful since they simplify the concepts and generate a visual image in a student’s mind that helps them to remember the information for a longer period of time.

So the above is all you need to complete this chapter, as there is nothing more to be done. If you fail to be open-minded while doing any of these things, you may miss valuable pieces of information that come your way.

Here you have it, in case you have questions regarding this or any of your Physics, Chemistry, or Mathematics topics, please log into DoubtConnect. Also, join the Discord community and you will be welcomed to the World of bootstrappers and your doubts will be solved free of cost!




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