Structure of Atom lesson plan CBE

 Competency Based Lesson/Unit Plan

1.              Name of the Teacher:                  Designation: PGT Chemistry                         

2.              Subject:         CHEMISTRY                            Class: 11                      Section:  A  

3.              Lesson/Unit Name: Structure of Atom                                                                     

4.              No. of periods required:14  Duration From:1/07/2026 To 15/7/2026

A.             Curricular Competencies to be developed (As per NCF-SE 2023)

 NCF 2023 suggests the Panchaadi (five-step) framework for lesson planning to achieve these competencies:

1.      Aditi (Introduction/Context Setting): Discovery of subatomic particles, atomic theories

2.      Bodh (Conceptual Understanding): Bohr’s theory and its limitation

3.      Abhyas (Practice): Active practice through problems on Bohr’s theory and dual nature of light

4.      Prayog (Application): Apply the knowledge of Quantum theory of atom to understand the distribution of electrons in an atom

5.      Prasar (Extension/Expansion): Expand the knowledge in writing electronic configuration using Aufbau Principle, Pauli’s exclusion principle and Hund’s multiplicity rule. Stability of half and fully filled orbitals.

B.             Learning Outcomes (Specific to the lesson mapped with NCERT learning outcomes):

Students will be able to learn

1. Understand:

a.      The experiments that led to the discovery of sub-atomic particles

b.      Properties of Electron, protons and neutrons

c.      Different models of atoms and their drawbacks

2. Determine the energy and radius of electron in nth orbit using Bohr’s model.

3. Recognize

a.      Dual nature of light, energy of photons using Planck’s theory

4.Define:

a.      Atomic number, atomic mass number, Isotopes and Isobars

b.      Photoelectric effect, Blackbody radiation

5. Problem solving:

a.      Drawbacks of Bohr’s theory,

b.      Heisenberg Uncertainty principle, de Broglie’s wavelength,

c.      Quantum mechanical model

d.      Quantum numbers, Stability of half-filled and fully filled orbitals

C.             Details of Pedagogical Strategies/Process (Art integrated /Sports integrated/ Story telling based/Toy based /Any other pedagogy):

1.      Art integrated activity: Making a chart of electronic configuration

2.      Toy based process: models of orbitals shown in video

https://youtu.be/Nr40fnfHccQ?si=cJl--NhwOES97LXB

https://youtu.be/ukGLH_NrFH8?si=CxF-MC_NoJddPpMv

https://youtu.be/S1LDJUu4nko

D.             Topic of the lesson for presentation by the students (once in a week by rearranging classroom setting suitable for group work):

1.       Assigning of Quantum numbers to different orbitals, Possible values of quantum numbers

E.             The 21st Century Skills to be developed:

Critical thinking: Dual nature of electron

Collaboration: Importance of understanding the models of atom

Problem solving: Calculation of wavelength, energy and radius

Technology literacy: Use of Olabs.

F.              Activities/Experiments/Hands-on-learning/Projects:

1.      Determination of melting point and boiling point

2.      Chart of different values of quantum numbers

G.             Interdisciplinary linkage and infusion of Life Skills, Values, Gender Sensitivity and Environmental Awareness:

1.      Application of Photoelectric effect in our daily life, Properties of light that explains dual nature of light

H.             Resources (including ICT):

NCERT textbook, Modern ABC, Physical Chemistry by Atkins, Olabs, Youtube videos related to the experiments, Google forms for assessment, Diksha portal for revision and references, PPT shared by Navodaya teachers, Material provided by Navodayasamiti, Questions available in websites such as Byjus, cbseguide, askiitiansetc to expose the students to different types of questions. Pictures or images available on the internet.

I.                Assessment items for measuring the attainment of learning outcomes in the class and as home assignments (Teacher should plan Assessment Items and link the same with learning outcomes mentioned in Para A):

Items	No of Items	Sl.No. of LO	Items	No of Items	Sl.No. of LO
Oral Quiz	-		Presentation	3	1-7
Portfolio	-		Puzzle	-
Multiple choice Questions	10	1 TO 7	Group Project	-
Very Short Answer Questions	10	1 TO 7	Individual Project	1
Short Answer Questions	10	1 TO 7	Any other Item
Long Answer Questions	5	1 TO 7
Compentancy based Questions	5	1 TO 7

Note: The teacher will keep the records of all assessment items.

 

J.              Remedial Teaching Plans/Plan for unfinished portion of previous unit:

1.      Extra classes will be taken if unable to complete the portion on time. A period will be dedicated to clear doubts and self-assessment of learning outcomes for every unit.Practice of previous year questions. Practice of competency based questions. Practice of Assertion-reason type of questions

K.             Inclusive Practices (Activities/Support measures for Differently abled students):

                              Not applicable

 

Date:1/7/2026                  (Signature of theteacher)

Remarks of the Principal/Vice Principal:

 

(Signature of the Principal/Vice Principal)

Images from slide share

Assessment questions

 

1.(i). Calculate the Number of Electrons Which Will Together Weigh One Gram.

(ii).Calculate the Mass and Charge of One Mole of Electrons.

 2.(i).Calculate the Total Number of Electrons Present in One Mole of Methane.

 (ii). a) Find the Total Number of Neutrons in 7mg of ¹⁴C.(Assume the Mass of a Neutron = 1.675×10⁻²⁷kg)

 (b) Find the Total Mass of Neutrons in 7mg of ¹⁴C . (Assume the Mass of a Neutron = 1.675×10−27kg )

(iii). (a) Find the Total Number of Protons in 34mg of NH3 at STP. 

 (b) Find the total mass of protons in 34mg of NH₃ at STP. Will the answer change if the temperature and pressure changed?

3. How Many Neutrons and Protons are there in the Following Nuclei?

¹³₆C,¹⁶₈O,²⁴₁₂Mg,⁵⁶₂₆Fe,⁸⁸₃₈Sr₆¹³C,₈¹⁶O,₁₂²⁴Mg,₂₆⁵⁶Fe,₃₈⁸⁸Sr

4. Write the Complete Symbol for the Atom with the Given Atomic Number (Z) and Atomic mass (A)

a. Z = 17, A = 35

b. Z = 92, A = 233

c. Z = 4, A = 9

5. Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (υ) and wave number ( υ− ) of the yellow light. 

 6.(i). Find energy of each of the photons which correspond to light of frequency 3×1015Hz3×1015Hz 

 (ii). Find energy of each of the photons which have wavelength of 0.50A^o 

7. Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0×10⁻¹⁰s 

8. What is the number of photons of light with a wavelength of 4000 pm that provide 1 J of energy?

9. A photon of wavelength 4×10⁷mstrikes on metal surface, the work function of the metal being 2.13eV. 

(i). Calculate the energy of photon (eV)

(ii). Calculate the kinetic energy of the emission.

(iii). Calculate the velocity of the photoelectron (1eV=1.6020×10−19J)

10. Electromagnetic radiation of wavelength 242 nm is just sufficient to ionize the sodium atom. Calculate the ionization energy of sodium in kJmol−1kJmol−1 

11.  A 25 watt bulb emits monochromatic yellow light of wavelength of 0.57μm . Calculate the rate of emission of quanta per second.

12. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength6800A⁰. Calculate threshold frequency (υ₀) and the work function (w₀) of the metal.

13. What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n =2?

14. How much energy is required to ionize a H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of the H atom (energy required to remove the electron from n =1 orbit).

15. What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?

16.(i). The energy associated with the first orbit in the hydrogen atom is −2.18×10¹⁸Jatom⁻¹. What is the energy associated with the fifth orbit?

(ii). Calculate the radius of Bohr’s fifth orbit for hydrogen atom.

17. Calculate the wave number for the longest wavelength transition in the Balmer series of atomic hydrogen.

18. What is the energy in joules required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is −2.18×10⁻¹¹ergs

19. The electron energy in hydrogen atom is given by E_n=(−2.18×10⁻¹⁸)n²J Calculate the energy required to remove an electron completely from the n = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?

20. Calculate the wavelength of an electron moving with a velocity of 2.05×107ms−1 

21. The mass of an electron is 9.1×10−31kg. If it is K.E. is 3.0×10−25J. Calculate its wavelength.

22. Which of the following are isoelectronic species i.e., those having the same number of electrons? Na+,K+,Mg+2,Ca+2,S−2,Ar 

23. (i). Write the Electronic Configurations of the Following ions:

(a) H−ion(b) Na+ion(c) O−2 ion(d) F− ion

(ii).What are the Atomic Numbers of Elements Whose Outermost Electrons are Represented by 

(a) 3s1 (b) 2p32p3 

(iii).Which Atoms are indicated by the Following Configurations?

(a) [He]2s1(b) [Ne]3s23p3

24. What is the Lowest Value of n That Allows G Orbitals To Exist?

25. An Electron Is in One of the 3D Orbitals. Give the Possible Values of n, l and m, for This Electron.

26. (i). An Atom of an Element Contains 29 Electrons and 35 Neutrons. Deduce the Number of Protons.

(II). An Atom of an Element Contains 29 Electrons and 35 Neutrons. Deduce the Electronic Configuration of the Given Element.

27. Give the Number of Electrons in the Species  He2+ , H2 and O2+ 

28.(i). An atomic orbital has n = 3. What are the possible values of l and ml?

(ii). List the quantum numbers (mlml and l) of electrons for 3d orbital.

(iii). Which of the following orbitals are possible? 

29. Using s, p, d notations, describes the orbital with the following quantum numbers.

a)  n = 1, l = 0;b)  n = 3; l =1c)  n = 4; l = 2;d)  n = 4; l =3.

30. Explain, Giving Reasons, Which of the Following Sets of Quantum Numbers are Not

A	n = 0	l = 0	ml = 0	ms=+1/2
B	n = 1	l = 0	ml = 0	ms=−1/2
C	n = 1	l = 1	ml = 0	ms=+1/2
D	n = 2	l = 1	ml = 0	ms=−1/2
E	n = 3	l = 3	ml= – 3	ms=+1/2
F	n = 3	l = 1	ml = 0	ms=+1/2

 

MCQ

1. Neutron was discovered by ————–

(a) J.J Thomson(b) Chadwick(c) Rutherford(d) Priestley

2. The nucleus of the atom consists of ————–

(a) Protons and neutrons(b) Protons and electrons

(c) Neutrons and electrons(d) Protons, neutrons and electrons

3. The radius of an atomic nucleus is of the order of————–

(a) 10^-10 cm(b) 10^-13 cm(c)10^-15 cm(d) 10^-8 cm

4. Isotopes of an element have ————–

(a) Different chemical and physical properties

(b) Similar chemical and physical properties

(c) Similar chemical but different physical properties

(d) Similar physical but different chemical properties

5. Which of the following pairs represents isobars?

(a) ³He₂ and ⁴He₂(b) ²⁴Mg₁₂ and ²⁵Mg₁₂(c) ⁴⁰K₁₉ and ⁴⁰Ca₂₀(d) ⁴⁰K₁₉ and ³⁹K₁₉

6. The atomic orbital is ————–

(a) The circular path of the electron(b) Elliptical shaped Orbit

(c) Three-dimensional field around nucleus

(d) The region in which there is a maximum probability of finding an electron

7. Principal, Azimuthal and magnetic quantum numbers are respectively related to:

(a) Size, shape and orientation(b) Shape, size and orientation

(c) Size, orientation and shape(d) None of the above

8. The electronic configuration of chromium (Z=24) is:

(a) [Ne] 3s² 3p⁶ 3d⁴ 4s²(b) [Ne] 3s² 3p⁶ 3d⁵ 4s¹

(c) [Ne] 3s² 3p⁶ 3d¹ 4s²(d) [Ne] 3s² 3p⁶ 4s² 4p⁴

9. According to Aufbau principle a new electron enters the orbitals when:

(a) (n + l) is minimum(b) (n + l) is maximum

(c) (n + m) is minimum(d) (n + m) is maximum

10. Which of the following is not permissible?

(a) n= 4, l = 3, m= 0(b) n= 4, l = 2, m= 1

(c) n= 4, l = 4, m= 1(d) n= 4, l = 0, m= 0