Most asked three mark questions Quantum Mechanical Model of Atom

11th Standard

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Chemistry

Time : 01:30:00 Hrs
Total Marks : 90

Part - A

31 x 3 = 93
1. An electron a proton which one will have a higher velocity to produce matter waves of the same wavelength? Explain it

2. Explain why the uncertainty principle is significant only for the motion of sub-atomic particles but is negligible for the macroscopic objects?

3. What are quantum numbers?

4. What is the maximum number of electrons that can be accommodated in a shell?

5. What is meant by nodal surface or node?

6. What is shape of the orbital with (i) n = 2 and = 0 ; (ii) n = 2 and I = 1?

7. Write the values of I and m for p-orbitals

8. Which quantum accounts for the orientation of the electron orbital?

9. Which energy level does not have p-orbital?

10. An atom of an element has 19 electrons. What is the total number of p-orbital?

11. How many electrons can have s+ 1/2 in a d-subshell?

12. Using s, p, d notations, describe the orbital with the following quantum numbers.
(i) n =1 ,l = 0 ,(ii) n = 3, l= 1 (iii)n = 4, l= 2 (iv) n =4 , l = 3

13. Which orbital in each of the following pairs is lower in energy?
(i) 2s,2p (ii) 3p < 3d (iii) 3s < 4s (iv) 4d < 5f

14. Discuss the similarities and differences between 1s and 2s-orbitals.

15. An atom of an element contains 29 electrons and 35 neutrons. Deduce
(i) the number of protons.
(ii) the electronic configuration of the element.

16. Which one among the following salts is more stable? Ferrous and ferric salts

17. Calculate the total number of angular nodes and radial nodes present in 3p-orbital.

18. An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom?

19. (i) State (n + 1) rule.
(ii) Arrange the orbials in the increasing order of energies based on (a) principal quantum number and (b) (n + 1) rule.

20. Explain, giving reasons which of the following sets of quantum numbers are not possible?
(i) n = 0, l= 0, m1 = 0, ms = + 1 /2
(ii) n= 1 l= 0 m1 = 0 ms$-\frac { 1 }{ 2 }$
(iii) n= 1 l= 1 m1 = 0 ms =$+\frac { 1 }{ 2 }$
(iv) n= 2 l= 1​​​​​ m1 = 0 ms =$-\frac { 1 }{ 2 }$
(v)  n= 3 l= ​3 ​​​​​​ m1 = ​​​​​​​-3  ms =​​​​​​​$+\frac { 1 }{ 2 }$
(vi)  n= 3,l =1,m1 = 0 ,ms =​​​​​​​$+\frac { 1 }{ 2 }$

21. Write down the quantum numbers n, and I for the following orbitals
(i) ${ 3d }_{ { x }^{ 2 }-y^{ 2 } }$  (ii) ${ 4d }_{ { z }^{ 2 } }$  (iii) ${ 3d }_{ { xy } }$  (iv) ${ 4d }_{ { xy } }$   (v) ${ 2p }_{ z }$   (vi) ${ 3p }_{ x }$

22. An atomic orbital has n = 3. What are the possible values of 1 and m1?

23. List the quantum numbers (m1 and l) of electrons for 3d-orbital.

24. Which atoms are indicated by the following configurations?
(a) [He]2s1   (b) [Ne]3s23p3  (c)[Ar]4s2 3d1

25. Which of the following orbitals are possible? 1p, 2s, 2p and 3f.

26. Write the electronic configurations of the following ions:
(a) H- (b) Na+ (c) O2- (d) F-

27. State Hund's rule of maximum multiplicity.

28. What are the atomic numbers of elements whose outermost electrons are represented by
(a) 3s2 (b) 2p3 (c) 3p5

29. Write note on the necessity for Hund's rule.

30. Discuss the filling of electron in a carbon atom

31. Using angular distribution function discuss the shapes of s orbitals