#### 11th Standard Chemistry Quantum Mechanical Model of Atom English Medium Free Online Test One Mark Questions 2020 - 2021

11th Standard

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Chemistry

Time : 00:20:00 Hrs
Total Marks : 20

20 x 1 = 20
1. Two electrons occupying the same orbital are distinguished by

(a)

azimuthal quantum number

(b)

spin quantum number

(c)

magnetic quantum number

(d)

orbital quantum number

2. The number of nodes in s orbital of any energy level is equal to

(a)

n

(b)

2n2

(c)

n-1

(d)

n-2

3. Which one of the following orbitals is spherical in shape?

(a)

4s

(b)

3p

(c)

3d

(d)

4f

4. A macroscopic particle of mass 100 g and moving at a velocity of 100 cm S-1 will have a de Broglie wavelength of

(a)

6.6 x 10-29 em

(b)

6.6 x 10-30 em

(c)

6.6 x 10-31 em

(d)

6.6 x 10-32 em

5. Match the list I with List II and select the correct answer using. the code given below the lists.

 List I List II A The energies of electrons are quantized 1 Thomson's atomic model B Atom is a positively charged sphere in which the electrons are embedded 2 Bohr atom model C Planetary model 3 De Broglie D Dual nature of the microscopic particles 4 Rutherford
(a)
 A B C D 1 3 2 4
(b)
 A B C D 4 3 1 2
(c)
 A B C D 3 1 4 2
(d)
 A B C D 2 1 4 3
6. How many neutrons and protons respectively are present  in the 6C13 nuclei?

(a)

6, 13

(b)

6, 7

(c)

13,6

(d)

7,6

7. 6C14 and 7N14 are

(a)

isotones

(b)

isoelectronic

(c)

isobars

(d)

isotopes

8. What is the maximum number of orbitals that can be identified with the following quantum numbers? n=3,l=1,m1=0

(a)

1

(b)

2

(c)

3

(d)

4

9. ${ \Psi }^{ 2 }$ = 0 represents:

(a)

a node

(b)

an orbital

(c)

angular wave function

(d)

wave function

10. Which of the following expressions represents the electron probability function?

(a)

$4\pi r dr{ \Psi }^{ 2 }$

(b)

$4\pi r^2 dr{ \Psi }$

(c)

$4\pi r^2 dr{ \Psi }^{ 2 }$

(d)

$4\pi r dr{ \Psi }$

11. The number of planar nodes in an orbital can be determined from the value of:

(a)

principal quantum number (n)

(b)

azimuthal quantum number (l)

(c)

both principal and magnetic quantum number (n, m)

(d)

magnetic quantum number (m)

12. Consider the following statements.
(i) The region where the probability density of electron is zero, called nodal surface.
(ii) The probability of finding the electron is independent of the direction of the nucleus.
(iii) The number of radial nodes is equal to n + 1+ 1
Which of the above statements is/are correct?

(a)

(i) and (iii)

(b)

(i) and (ii)

(c)

(iii) only

(d)

(i) and (iii)

13. Which of the following is the expected configuration of Cr (Z = 24)?

(a)

1s2 2s2 2p6 3s2 3p6 3d4 4s2

(b)

1s2 2s2 2p6 3s2 3p6 3d5 4s1

(c)

1s2 2s2 2p6 3s2 3p6 3d6

(d)

1s2 2s2 2p6 3s2 3p6 3d5 4s3

14. The energy of an electron of hydrogen atom in 2nd main shell is equal to________________

(a)

-13.6 eV atom-1

(b)

-6.8 eV atom-1

(c)

-0.34 eV atom-1

(d)

-3.4 eV atom-1

15. The energy of an electron of hydrogen atom in 4th main shell in terms of kJ mol -1 is_______________

(a)

-1312.8 kJ mol-1

(b)

-82.05kJ mol-1

(c)

-328.2kJ mol-1

(d)

-656.4kJ mol-1

16. The maximum number of electrons that can be accommodated in N shell is_____________

(a)

8

(b)

18

(c)

32

(d)

36

17. What is the formula used to calculate the angular momentum?

(a)

$\sqrt{l(l+1)}{h\over 2\pi}$

(b)

$mvr\over 2\pi$

(c)

$mvr\over 2$

(d)

m.$\triangle v$

18. What are the values of n, I, m and s for 3px electron?

(a)

3,2,1,0

(b)

3,1,-1,+1/2

(c)

3,2,+1,-1/2

(d)

3,0,0,+1/2

19. In a sodium atom (atomic number = 11 and mass number = 23) and the number of neutrons is___________.

(a)

equal to the number of protons

(b)

less than the number of protons

(c)

greater than the number of protons

(d)

none of these

20. The outermost electronic configuration of manganese (at. no. = 25) is___.

(a)

3d5 4s2

(b)

3d6 4s1

(c)

3d7 4so

(d)

3d6 4s2