#### Quantum Mechanical Model of Atom One Mark Questions

11th Standard

Reg.No. :
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Chemistry

Time : 00:45:00 Hrs
Total Marks : 30
30 x 1 = 30
1. The energy of light of wavelength 45 nm is

(a)

6.67 x 1015J

(b)

6.67 x 1011J

(c)

4.42 x 10-18J

(d)

4.42 x 10-15J

2. The energies E1and E2 of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths ie $\lambda$1 and$\lambda$2 will be

(a)

$\frac { { \lambda }_{ 1 } }{ { \lambda }_{ 2 } } =1$

(b)

${ \lambda }_{ 1 }=2{ \lambda }_{ 2 }$

(c)

${ \lambda }_{ 1 }=\sqrt { 25\times 50{ \lambda }_{ 2 } }$

(d)

$2{ \lambda }_{ 1 }={ \lambda }_{ 2 }$

3. Splitting of spectral lines in an electric field is called

(a)

Zeeman effect

(b)

Shielding effect

(c)

Compton effect

(d)

Stark effect

4. The electronic configuration of Eu (Atomic no. 63) Gd (Atomic no. 64) and Tb (Atomic no. 65) are

(a)

[Xe] 4f6 5d' 6s2, [Xe] 4f7 Sd1 6s2 and [Xe] 4f8  5d1 6s2

(b)

[Xe] 4f7 , 6s2, [Xe] 4f7 5d1 6s2 and [Xe] 4f9 6s2

(c)

[Xe] 4f7 ,6s2, [Xe] 4f7 6s2 and [Xe] 4f7 5d1 6s2

(d)

[Xe] 4fSd1 6s2, [Xe] 4f7 5d1 6s2 and [Xe] 4f9 6s2

5. Which of the following pairs of d-orbitals will have electron density along the axes ?

(a)

dz2, dxz

(b)

dxz, dyZ

(c)

dz2, dx2-y2

(d)

dxy ,dx2-y2

6. 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

7. For d-electron, the orbital angular momentum is

(a)

$\frac { \sqrt { 2 } h }{ 2\pi }$

(b)

$\\ \frac { \sqrt { 2h } }{ 2\pi }$

(c)

$\frac { \sqrt { 2\times 4 } h }{ 2\pi }$

(d)

$\frac { \sqrt { 2\times 4 } h }{ 2\pi }$

8. How many nodes are possible for 2s orbital?

(a)

1

(b)

2

(c)

3

(d)

zero

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

(a)

4s

(b)

3p

(c)

3d

(d)

4f

10. Which of the following has maximum number of unpaired d-electrons?

(a)

N3+

(b)

Fe2+

(c)

Zn+

(d)

Cu+

11. How many electrons in an atom with atomic number 105 can have (n + I) = 8 ?

(a)

30

(b)

17

(c)

15

(d)

unpredictable

12. Electron density in the yz plane of 3dxy-y2 orbital is

(a)

zero

(b)

0.50

(c)

0.75

(d)

0.90

13. If uncertainty in position and momentum are equal, then minimum uncertainty in velocity is

(a)

$\frac { 1 }{ m } \sqrt { \frac { h }{ \pi } }$

(b)

$\sqrt { \frac { h }{ \pi } }$

(c)

$\frac { 1 }{ 2m } \sqrt { \frac { h }{ \pi } }$

(d)

${ \frac { h }{4\pi } }$

14. Which of the following does not represent the mathematical expression for the Heisenberg uncertainty principle?

(a)

$\triangle x.\triangle p\ge \frac { h }{ 4\pi }$

(b)

$\triangle x.\triangle v\ge \frac { h }{ 4\pi m }$

(c)

$\triangle E.\triangle t\ge \frac { h }{ 4\pi }$

(d)

$\triangle E.\triangle x\ge \frac { h }{ 4\pi }$

15. J. J. Thomson's cathode ray experiment revealed that atoms consist of

(a)

electrons

(b)

protons

(c)

neutrons

(d)

photons

16. The nucleus of an atom contains

(a)

Electrons and protons

(b)

Neutrons and protons

(c)

Electrons, protons and neutrons

(d)

Neutrons and electrons

17. The atomic number of an element is 17 and its mass number is 37. The number of protons, electrons and neutrons present in the  neutral atom are:

(a)

17,37,20

(b)

20,17,37

(c)

17,17,20

(d)

17,20,17

(e)

37,20,17.

18. Mass number is equal to the _

(a)

number of protons + number of electrons

(b)

number of protons + number of neutrons

(c)

number of neutrons + number of electrons

(d)

number of electrons

19. The fixed circular paths around the nucleus are caused _

(a)

orbits

(b)

Orbitals

(c)

nucleons

(d)

Mesons

20. Neutrons was discovered by

(a)

Rutherford

(b)

(c)

Bohr

(d)

Thomson

21. 6C14 and 7N14 are

(a)

isotones

(b)

isoelectronic

(c)

isobars

(d)

isotopes

22. Which of the following conclusions could not be derived from Rutherford's $\alpha$-particle scattering experiment?

(a)

Most of the space in the atom is empty.

(b)

The radius of the atom is about 10-10 m while that of the nucleus is 10-15 m

(c)

Electrons move in a circular path of fixed energy called orbits.

(d)

Nucleus and the electrons are held together by electrostatic force of attraction

23. Which of the following about the electron is incorrect?

(a)

It is a negatively charged particle.

(b)

The mass of electron is equal to the mass of neutron .

(c)

It is a basic constituent of all the atoms

(d)

electron mass = 9.10938356 x 10-31kilograms

24. Which of the following properties of atom could be explained correctly by Thomson model of an atom?

(a)

Overall neutrality of atom.

(b)

Spectra of hydrogen atom.

(c)

Position of protons, electrons and neutrons in atom .

(d)

Stability of atom.

25. If En = -313.6/n2,If the value of Ei = -34.84 to which value 'n' corresponds

(a)

4

(b)

3

(c)

2

(d)

1

26. Dual character of an electron was explained by

(a)

Bohr

(b)

Heisenberg

(c)

de-Broglie

(d)

Pauli

27. de-Broglie equation is

(a)

λ = mv/h

(b)

λ = hmv

(c)

λ = hv/m

(d)

λ =h/mv

28. The value of Bohr radius for hydrogen atom is

(a)

0.529 $\times$ 10-8 cm

(b)

0.529 $\times$ 10-10 cm

(c)

0.529 $\times$ 10-12 cm

(d)

0.529 $\times$ 10-12 cm

29. Which of the following particle having same kinetic energy, would have the maximum de-Broglie wave length

(a)

α-particle

(b)

proton

(c)

β-particle

(d)

neutron

30. Electronic configuration of species M2+ is 1s2 2s2 2p6 3s2 3p6 3d6 and its atomic weight is 56. The number of neutrons in the nucleus of species M is:

(a)

26

(b)

22

(c)

30

(d)

24