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Question Bank No: 1

1. Which of the following sets of quantum numbers, represent the 19th electron of chromium?

a)		$\begin{matrix} n = 3, & l = 0, & m = 0, & s = 1 / 2 \end{matrix}$
b)		$\begin{matrix} n = 3, & l = 2, & m = - 2, & s = 1 / 2 \end{matrix}$
c)		$\begin{matrix} n = 4, & l = 0, & m = 0, & s = 1 / 2 \end{matrix}$
d)		$\begin{matrix} n = 4, & l = 1, & m = - 1, & s = 1 / 2 \end{matrix}$

2. The mass of the proton is 1840 times of electron its potential difference is 1KV. The kinetic energy of proton is

a)		1840 KeV
b)		1 KeV
c)		$\frac{1}{1840} KeV$
d)		920KV

3. Which of the following is not paramagnetic

a)		$O_{2}$
b)		$O_{2}^{+}$
c)		$O_{2}^{2 -}$
d)		$O_{2}^{-}$

4. The electronic configuration of element having atomic number 37 is

a)		(2,8) 3 $s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 5 s^{1}$
b)		(2,8)3 $s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 5 s^{6} 4 p^{5}$
c)		(2,8)3 $s^{2} 3 p^{6} 4 s^{2} 3 d^{9} 5 s^{1} 4 p^{5}$
d)		none of these

5. Uncertainly in the position of an electron (mass=9.1 $\times 10^{- 31}$ kg) moving with a velocity 300 ${ms}^{- 1}$ ,accurate upto 0.001%, will be

a)		19.2 $\times 10^{- 2} m$
b)		5.76 $\times 10^{- 2} m$
c)		19.2 $\times 10^{- 2} m$
d)		3.84 $\times 10^{- 2} m$

6. According to Bohr's theory,the angular momentum of an electron in $5^{th}$ orbit is

a)		25h/ $π$
b)		1.0h/ $π$
c)		10h/ $π$
d)		2.5h/ $π$

7. An electron is present in 4f subshell.The possible values of azimuthal quantum number for this electron are

a)		0,1,2,3
b)		1,2,3,4
c)		3
d)		4

8. The energy of the second orbit of hydrogen is equal to the energy of

a)		Fourth orbit of ${He}^{+}$
b)		Fourth orbit of ${Li}^{2 +}$
c)		Second orbit of ${He}^{+}$
d)		Second orbit of ${Li}^{2 +}$

9. Azimuthal quantum number of last electron of ${}_{11}{Na}$ is

a)		1
b)		2
c)		3
d)		0

10. The spectrum of ${He}^{+}$ is expected to be similar to that of

a)		$H_{2}$
b)		${Li}^{+}$
c)		Na
d)		He

11. Wave character of electrons was experimentally verified by

a)		Einstein
b)		de Broglie
c)		Max Planck
d)		Davisson and Germer

12. The ratio of the energy of a photon of 200 nm wavelength radiation to that of 400 nm radiation is

a)		1/4
b)		5
c)		1/2
d)		2

13. Which of the following subshells is not permitted?

a)		4f
b)		4d
c)		3s
d)		4g

14. A subshell with n=6, 1=2 can accomodate a maximum of

a)		12 electrons
b)		36 electrons
c)		10 electrons
d)		72 electrons

15. The energy required to dislodge an electron from excited isolated H-atom is (I $E_{1}$ =13.6eV)

a)		Equal to13.6eV
b)		>13.6eV
c)		$\leq$ 13.6eV
d)		<13.6 and >3.4eV

16. The ratio of the energy of a photon of 2000A wavelength radiation to that of 4000 A radiation is

a)		$-_{4}^{1}$
b)		4
c)		$-_{2}^{1}$
d)		2

17. Nitrogen atom has 3 unpaired electrons, because of

a)		Hund's rule
b)		Uncertainty Exclusion Principle
c)		Pauli's Exclusion Principle
d)		Aufbau's Rule

18. The designation of the orbital with n=3 and l=2 is

a)		4d
b)		5d
c)		3d
d)		5s

19. The number of unpaired electrons in ferrous ion is

a)		3
b)		2
c)		4
d)		5

20. The maximum kinetic energy of photo-electrons is inversely proportional to ..........of incident radiation

a)		intensity
b)		wavelength
c)		frequency
d)		amplitude

21. In phosphorous atom (Z=15) in ground state, the numbers of occupied subshells and occupied orbitals are respectively

a)		3,3
b)		5,9
c)		5,5
d)		3,6

22. Neutrons were discovered by

a)		J.J Thomson
b)		Rutherford
c)		James Chadwick
d)		G.T. Seabery

23. The number of electrons with quantum numbers n=3 and l=2 in chromium is

a)		8
b)		6
c)		5
d)		7

24. How many electrons in calcium have l=0?

a)		6
b)		8
c)		10
d)		12

25. In a multi-electron atom, the energy of the electron in a particular orbital is determined by

a)		n only
b)		l only
c)		n and l
d)		n,l and m

26. A body of mass 10mg is moving with a velocity of 100m $s^{- 1}$ . The wavelength of the de Broglie wave associated with it would be

a)		6.63 $\times 10^{- 37}$ m
b)		6.63 $\times 10^{- 31}$ m
c)		6.63 $\times 10^{- 34}$ m
d)		6.63 $\times 10^{- 35}$ m

27. The maximum number of electrons with clockwise spin that can be accomodated in a f-subshell is

a)		14
b)		7
c)		5
d)		10

28. The wavelength of the radio-waves having frequency 3 MHz would be

a)		100m
b)		300m
c)		100nm
d)		300nm

29. ${}_{11}^{23}{Na}$ and ${}_{12}^{24}{Mg}$ are

a)		Isotopes
b)		Isobars
c)		Isodiaphers
d)		Isotones

30. The set of quantum number not applicable for an electron in an atom is

a)		n=1, l=1, m=1, s=+1/2
b)		n=1, l=0, m=0, s=+1/2
c)		n=1, l=0, m=0, s=-1/2
d)		n=2, l=0, m=0, s=+1/2

31. The quantum number values for the last unpaired electrons of chlorine are

a)		n=3, l=0, m=0, s=-1/2
b)		n=3, l=1, m=2, s=-1/2
c)		n=3, l=1, m=+1, s=+1/2
d)		n=3, l=0, m=-1, s=-1/2

32. Gamma rays are

a)		High energy electrons
b)		Low energy electrons
c)		High energy electromagnetic waves
d)		High energy positrons

33. Method to determine atomic numbers was devised by

a)		J.J Thomson
b)		H.G.J Moseley
c)		R. Milikan
d)		Rutherford

34. Rutherford's experiment of $α$ -particles showed for the first time that atom has

a)		protons
b)		neutrons
c)		nucleus
d)		electrons

35. Out of the following radiations, which one is most easily stopped by air

a)		X-rays
b)		$α$ -rays
c)		$β$ -rays
d)		$γ$ -rays

36. Particles cathode rays have same charge to mass ratio as

a)		$α$ - rays
b)		$β$ -rays
c)		$γ$ -rays
d)		Protons

37. The ratio of radius of the nucleus to the radius of the atom is of the order of

a)		$10^{5}$
b)		$10^{6}$
c)		$10^{- 5}$
d)		$10^{10}$

38. The quantum number not obtained from the Schrodinger wave equation is

a)		n
b)		l
c)		m
d)		s

39. If uncertainity in the position of electron is Zero, the uncertainity in its momentum would be

a)		Zero
b)		$\geq \frac{h}{4 π}$
c)		$<$ $\frac{h}{4 π}$
d)		infinite

40. In hydrogen atom, the energy of an electron is determined by quantum number/s

a)		n
b)		n and l
c)		n, l and m
d)		n, l, m and s

41. An electron has spin quantum number, s = + $\frac{1}{2}$ and magnetic quantum number, m = +1. It cannot be present in

a)		s-orbital
b)		p-orbital
c)		d-orbital
d)		f-orbital

42. The ratio of radius of the nucleus to the radius of the atom is of the order of

a)		$10^{5}$
b)		$10^{6}$
c)		$10^{- 5}$
d)		$10^{- 8}$

43. Which electronic transition in hydrogen atom is accompanied by maximum release of energy?

a)		n = 2 to n = 1
b)		n = 3 to n = 2
c)		n = 4 to n = 3
d)		n = 4 to n = 2

44. The radius of the first orbit of hydrogen is 0.53 A .The radius of second orbit would be

a)		1.06 A
b)		2.12 A
c)		0.53 A
d)		0.26 A

45. In chromium atom, in ground state,the number of occupied orbitals is

a)		14
b)		15
c)		7
d)		12

46. The number of orbitals in the fourth energy level is

a)		4
b)		16
c)		32
d)		9

47. The energy of a photon of radiation having wavelength 3000 Ais nearly

a)		6.63 x $10^{- 19}$ J
b)		6.63 x $10^{- 18}$ J
c)		6.63 x $10^{- 16}$ J
d)		6.63 x $10^{- 49}$ J

48. The ionization potential of hydrogen from ground state to the first excited state is

a)		-13.6 eV
b)		10.2 eV
c)		-3.4 eV
d)		3.4 eV

49. The triad of nuclei is isotonic is

a)		6 $C^{14}, 7 N^{15}, 9 F^{17}$
b)		6 $C^{12}, 7 N^{14}, 9 F^{18}$
c)		6 $C^{14}, 7 N^{14}, 9 F^{17}$
d)		6 $C^{12}, 7 N^{14}, 9 F^{19}$

50. Electromagnetic radiation with maximum wavelength is

a)		Ultraviolet rays
b)		Radiowaves
c)		X-Rays
d)		Infrared