NCERT Class 12 Physics Solutions: Students of Class 12 can refer to this article to get NCERT Solutions for Class 12 Physics Chapter 12. These solutions will be helpful in understanding Chapter 12 Atoms. The NCERT Solutions for Class 12 Chapter 12 Atoms will include all unsolved theories and numerical problems. Read to get NCERT solutions for Class 12 Physics, Chapter 12 all exercises.
Read: NCERT Class 12 Physics Solutions
Read: CBSE Class 12 Physics Syllabus 2023-24
Read: RBSE Class 12 Physics Syllabus 2023-24
Read: Punjab Board Class 12 Physics Syllabus 2023-24
The objective is to helping students regarding the pattern of answering the question as per the cbse latest marking scheme.
Atoms Solutions
Some questions of this chapter are given here.
Q. Suppose you are given a chance to repeat the alpha-particle scattering experiment using a thin sheet of solid hydrogen in place of the gold foil. (Hydrogen is a solid at temperatures below 14 K.) What results do you expect?
Sol.
There would be no large-angle scattering, because the alpha-particle has mass nearly four times than that of the target nuclei. No observable conclusion can be made in this solid hydrogen alpha-particle scattering experiment.
Q. A difference of 2.3 eV separates two energy levels in an atom. What is the frequency of radiation emitted when the atom make a transition from the upper level to the lower level?
Sol.
Given:
E = 2.3 eV
We know
v = E / h
Substitution produces
v = 5.55 x 1014 Hz
Q. Choose the correct alternative from the clues given at the end of the each statement:
a)The size of the atom in Thomson’s model is .......... the atomic size in Rutherford’s model. (much greater than/no different from/much less than.)
b)In the ground state of .......... electrons are in stable equilibrium, while in .......... electrons always experience a net force. (Thomson’s model/ Rutherford’s model.)
c)A classical atom based on .......... is doomed to collapse. (Thomson’s model/ Rutherford’s model.)
d)An atom has a nearly continuous mass distribution in a ..........but has a highly non-uniform mass distribution in ..........(Thomson’s model/ Rutherford’s model.)
e)The positively charged part of the atom possesses most of the mass in .......... (Rutherford’s model/both the models.)
Sol.
a)No different from
b)Thomson’s model; Rutherford’s model
c)Rutherford’s model
d)Thomson’s model; Rutherford’s model
e)Both the models
The answers to these questions and many more are given in the PDF attached in the below link. Click to see the answers.
NCERT Rationalised Content Chapter: Atoms
| Chapter Name |
Page No. |
Deleted Topics |
| Chapter 12: Atoms |
421–422 |
12.3.1 Spectral Series |
| 424–426 |
12.4 Bohr Model of the Hydrogen Atom (retain only the expression for radius of nth possible orbit but delete its derivation) |
|
| 429 |
12.5 The Line Spectra of the Hydrogen Atom (retain only qualitative treatment) |
|
| 430 |
Example 12.6 |
|
| 436–437 |
Exercises 12.3, 12.11–12.17 |
CBSE Class 12 Physics Updated Question Paper Design 2023-24
| Typology of Questions |
Total Marks |
Approximate % |
| Remembering: Exhibit memory of previously learned material by recalling facts, terms, basic concepts, and answers. Understanding: Demonstrate understanding of facts and ideas by organising, comparing, translating, interpreting, giving descriptions, and stating main ideas. |
27 |
38 |
| Applying: Solve problems to new situations by applying acquired knowledge, facts, techniques and rules in a different way. |
22 |
32 |
| Analysing: Examine and break information into parts by identifying motives or causes. Make inferences and find evidence to support generalisations. Evaluating: Present and defend opinions by making judgments about information, validity of ideas, or quality of work based on a set of criteria. Creating: Compile information together in a different way by combining elements in a new pattern or proposing alternative solutions. |
21 |
30 |
| Total |
70 |
100 |
| Practical |
30 |
|
| Gross Total |
100 |
|
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