Jee 2014 Booklet1 Hwt Atomic Structure

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DATE : IITJEE : MARKS :

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TIME : 25 MINUTES

NAME : TEST CODE : At.Str [1]

ROLL NO. START TIME : END TIME : TIME TAKEN:

STUDENT’S SIGNATURE : PARENT’S SIGNATURE :

 This test contains a total of 10 Objective Type Questions.  Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. Compared to the mass of lightest nuclei, the mass of an electron is only (app.)

(A) 1/80 (B) 1/800 (C) 1/1800 (D) 1/2800

2. Which of the following is isoelectronic with carbon atom?

(A) N+ (B) O2 (C) Na+ (D) Al3+

3. When -particles are sent through a thin metal foil, most of them go straight through the foil because

(A) most part of the atom is empty space

(B) alpha particles move with high speed

(C) alpha particles are much heavier than electrons

(D) alpha particles are positively charged

4. Which of the following transitions are not allowed in the normal electronic emission spectrum of an atom?

(A) 1s2s (B) 2p1s (C) 5d4p (D) 5p3s

5. In photoelectric effect, the number of photoelectrons emitted is proportional to :

(A) intensity of incident beam (B) frequency of incident beam

(C) wavelength of incident beam (D) All of the above

6. Einstein’s photoelectric equation states that k

E hv W Here, Ek refers to :

(A) kinetic energy of all ejected electrons (B) mean kinetic energy of emitted electrons

(C) minimum kinetic energy of emitted electrons (D) maximum kinetic energy of emitted electrons

7. The maximum kinetic energy of the photoelectrons is found to be 6.63 10 19J. When the metal is irradiated with a radiation of frequency 2 × 1015_{Hz, the threshold frequency of the metal is about.}

(A) 2 10 15s1 (B) 1 10 15s1 (C) 2.5 10 15s1 (D) 4 10 15s1

8. Bohr’s theory is applicable to :

(A) He (B) Li2+ (C) He2+ (D) None of these

9. If r is the radius of first orbit, the radius of nthorbit of he H atom will be :

(A) r n2 (B) r n (C) r

n (D) r

2 n2

10. The principal quantum number of H-atom orbital, if the electron energy is 3.4 eV, will be :

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1. Which of the following electron transition in hydrogen atom will require largest amount of energy?

(A) From n = 1 to n = 2 (B) From n = 2 to n = 3

(C) From n to n1 (D) From n = 3 to n = 5

2. The wave nature of electron is verified by

(A) de-Broglie (B) Davisson and Germer (C) Rutherford (D) All of these

3. The mass of an electron is m, its charge is e and it is accelerated from rest through a potential difference, V. The velocity of electron will be calculated by formula : (A) V m (B) eV m (C) 2eV m       (D) None of these

4. The uncertainty in momentum of an electron is1 10 5kg m / s. The uncertainty in its position will be

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h6.621034kg m / s2

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(A) 2.36 10 28m (B) 5.25 10 28m (C) 2.271030m (D) 5.271030m

5. If the kinetic energy of an electron is increased four times, the wavelength of the de-Broglie wave associated with it would becomes :

(A) half times (B) 1

4 times (C) four times (D) two times

6. The two electrons in K-sub shell will differ in :

(A) principal quantum number (B) azimuthal quantum number

(C) magnetic quantum number (D) spin quantum number

7. The number of orbitals present in the shell with n = 4 is :

(A) 8 (B) 16 (C) 18 (D) 32

8. The number of electrons in the valence shell of calcium is :

(A) 2 (B) 4 (C) 6 (D) 8

9. The ground state electronic configuration of nitrogen atom can be represented as :

(A) (B)

(C) (D) All of the above

10. How many unpaired electrons are present in Ni2+ cation? (At. No. = 28)

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1. An electron, a proton and an alpha particle have KE of 16E, 4E and E respectively. What is the qualitative order of their de-Broglie wavelengths ?

(A)    _e _p _ (B)    _p _ _e (C)    _p _e _ (D)    _ _e _p 2. If the shortest wavelength of H-atom in Lyman series is x, the longest wavelength in Balmer series of He+ is :

(A) 36x 5 (B) 5x 9 (C) x 4 (D) 9x 5

3. Which of the following sets of quantum numbers represents the highest energy of an atom?

(A) n = 3, l = 1, m = 1, s = +1/2 (B) n = 3, l = 2, m = 1, s = +1/2

(C) n = 4, l = 0, m = 0, s = +1/2 (D) n = 3, l = 0, m = 0, s = +1/2

4. According to Bohr’s theory, the angular momentum of an electron in 5th orbit is :

(A) 25h  (B) h 1.0  (C) h 10  (D) h 2.5 

5. If the energy difference between the ground state of an atom and in excited state is 4.4 10 4J, the wavelength of photon required to produce the transition is :

(A) 2.26 10 12m (B) 1.13 10 12m (C) 4.52 10 16m (D) 4.52 10 12m

6. The orbital angular momentum of an electron in 3s orbital is :

(A) 1 h. 2 2 (B) h 2 (C) 1 h . 3 2 (D) zero

7. The orbital angular momentum of an electron revolving in a p-orbital is :

(A) zero (B) h 2 (C) h 2 (D) 1 h 2 2

8. The number of radial nodes of 3s and 2s orbital are respectively :

(A) 2, 1 (B) 0, 2 (C) 1, 2 (D) 2, 11

9. In a multi-electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic and electric field?

(A) n = 1, l = 0, m = 0 (B) n = 2, l = 0, m = 0 (C) n = 2, l = 1, m = 1 (D) n = 3, l = 2, m = 1

10. The uncertainty in the momentum of an electron is1.0 10 5kg ms1. The uncertainty in its position will be :

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(A) It is nucleus of deuterium (B) It is an ionised hydrogen atom

(C) It is an ionized hydrogen molecules (D) It is an particle

2. When a gold sheet is bombarded by a beam of  particles, only a few of them get deflected, whereas most go straight, undeflected. This is because :

(A) the force of attraction exerted on particle by electrons in insufficient

(B) the volume of nucleus is smaller than atom

(C) the force of repulsion acting on fast moving  particleis very small

(D) the neutrons have no effect on particle

3. The charge to mass ratio of particlesis approximately ….. the charge to mass ratio of protons :

(A) six times (B) four times (C) half (D) two times

4. Which of the following atoms has same number of protons and neutrons in its nucleus?

(A) Carbon (B) Deuterium (C) Tritium (D) Nitrogen

5. The radius of which of the following orbit is same as that of the first Bohr’s orbit of hydrogen atom?

(A) Li2+ (n = 2) (B) Li2+ (n = 3) (C) Be3+ (n = 2) (D) He+ (n = 2)

6. According to Bohr’s theory, the angular momentum for an electron of 3rd orbit is :

(A) 3 h (B) 1.5 h (C) 9 h (D) 2h

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7. The number of waves in an orbit are :

(A) n2 (B) n (C) n1 (D) n2

8. The magnitude of the spin angular momentum of an electron is given by :

(A) S s s

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1

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h 2    (B) h S s 2   (C) S 3 h 2 2    (D) None of these

9. The ratio of kinetic energy and total energy of an electron in a Bohr orbit of a hydrogen like species is :

(A) 1 (B) 1 (C) 2 (D) 1

2 

10. Which of the following sets of quantum number is correct?

(A) n 5, 4, m 0, s 1 2 l      (B) n 3, 3, m 3, s 1 2 l       1           

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1. The correct set of four quantum numbers for outermost electron of potassium (Z = 19) is :

(A) 4 1 0 1 2 , , , (B) 3 1 0 1 2 , , , (C) 4 0 0 1 2 , , , (D) 3 0 0 1 2 , , ,

2. A body of mass x kg is moving with a velocity is 100 ms1. Its de-Broglie wavelength is 6 62. 1035m. Hence, x is : (h6.621034Js)

(A) 0.1 kg (B) 0.25 kg (C) 0.15 kg (D) 0.2 kg

3. The number of photons emitted per second by a 60 W source of monochromatic light of wavelength 663 nm is : (h6.63 10 34Js)

(A) 41020 (B) 1.5 10 20 (C) 3 10 20 (D) 2 10 20

4. The ionisation enthalpy of hydrogen atom is 1.31210 J mol6 1. The energy required to excite the electron in the atom from n = 1 to n = 2 is :

(A) 8.51 10 J mol 5 1(B) 6.56 10 J mol 5 1(C) 7.56 10 J mol 5 1 (D) 9.84 10 J mol 5 1

5. Time period of a wave is5103s, what is the frequency ?

(A) 5103s1 (B) 2 10 s 2 1 (C) 23 10 s 3 1 (D) 5 10 s 2 1

6. Splitting of spectrum lines in magnetic field is :

(A) Stark effect (B) Raman effect (C) Zeeman effect (D) Rutherford effect

7. An electron from one Bohr stationary orbit can go to next higher orbit :

(A) by emission of electromagnetic radiation

(B) by absorption of any electromagnetic radiation

(C) by absorption of electromagnetic radiation of particular frequency

(D) without emission or absorption of electromagnetic radiation

8. The values of four quantum number of valence electron of an element are n = 4 l = 0, m = 0 and s 1 2

  . The element is :

(A) K (B) Ti (C) Na (D) Sc

9. An isobar of ₂₀Ca40 is :

(A) ₁₈Ar40 (B) ₂₀Ca38 (C) ₂₀Ca42 (D) ₁₈Ar38

10. The energy of second Bohr orbit of the hydrogen atom is 328 kJ mol1; hence the energy of fourth Bohr orbit would be :

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1. The orbital angular momentum of an electron in a d-orbital is : (A) 6 h 2 (B) h 2 2 (C) h 2 (D) 2h 2

2. The radius of the first Bohr orbit of hydrogen atom is 0.520 Å . The radius of the third orbit of Hwill be :

(A) 8.46 Å (B) 0.705Å (C) 1.59 Å (D) 2.38 Å

3. Which one of the following sets of ions represents a collection of isoelectronic species?

(A) K , Cl , Ca  2, Sc3 (B) Ba2, Sr2, K , S 2

(C) N3,O2, F , S 2 (D) Li , Na , Mg  2, Ca2

4. For a Bohr atom angular momentum M of the electron is (n = 0, 1, 2 …)

(A) 2 nh 4 (B) 2 2 n h 4 (C) 2 nh 4 (D) nh 2

5. The H-spectrum show :

(A) Heisenberg’s uncertainty principle (B) diffraction

(C) polarisation (D) presence of quantized energy level

6. Which of the following statements does not form a part of Bohr’s model of hydrogen atom?

(A) Energy of the electrons in the orbit is quantized

(B) The electron in the orbit nearest the nucleus has the lowest energy

(C) Electrons revolve in difference orbits around the nucleus

(D) The position and velocity of the electrons in the orbit cannot be determined simultaneously

7. Electrons will first enter into the set of quantum numbers n = 4, l = 0 or n = 3, l = 2

(A) n = 5, l = 0 (B) both possible (C) n = 3, l = 2 (D) data insufficient

8. An isotone of76₃₂Ge is :

(A) ₃₂77Ge (B) ₃₃77As (C) ₃₄77Se (D) ₃₆78Sc

9. Which of the following sets of quantum number is allowable:

(A) n2,l1, m0, s 1/ 2 (B) n2,l2, m 1, s 1/ 2

(C) n2,l1, m1, s 1/ 2 (D) n2,l1, m0, s0

10. The transition of electrons in H atom that will emit maximum energy is :

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1. Which out of the following configurations is incorrect?

(A) 1s22s22p_x22p2_y2p 1_z0 (B) 1s22s22p1_x2p1_y

(C) 1s22s22p1_x2p1_y2p1_z (D) 1s22s22p63s23p63d54s1 2. Which of the following set of quantum numbers is an impossible arrangement?

(A) n3, m 2, s 1 2/ (B) n4, m3, s 1 2/ (C) n5, m2, s 1 2/ (D) n3, m 3, s 1 2/

3. If the energy of electron in H atom is given by expression, 1312 / n kJ mol2 1, then the energy required to excite the electron from ground state to second orbit is :

(A) 328 kJ (B) 656 kJ (C) 984 kJ (D) 1312 kJ

4. Which of the following sets of quantum numbers is not possible?

(A) n4,l1, m0, s 1/ 2 (B) n4,l3, m 3, s 1/ 2

(C) n4,l1, m 2, s 1/ 2 (D) n4,l1, m0, s 1/ 2

5. A cricket ball of 0.5 kg is moving with a velocity of100 ms1. The wavelength associated with its motion is :

(A) 1/100 cm (B) 66 10 34m (C) 1.32 10 35m (D) 6.61028m

6. The work function of a metal is 4.2 eV. If radiations of 2000 Å fall on the metal, then the kinetic energy of the fastest photoelectron is:

(A) 1.6 10 19J (B) 16 10 10J (C) 3.2 10 19J (D) 6.4 10 10J

7. The number of spherical nodes in 4s orbital is :

(A) 4 (B)  (C) 2 (D) 3

8. The ratio of the radii of the three Bohr orbits is :

(A) 1 : 1/ 2 : 1/3 (B) 1 : 2 : 3 (C) 1 : 4 : 9 (D) 1 : 8 : 27

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

(A) 30 (B) 17 (C) 15 (D) Unpreditable

10. If the threshold wavelength ( for ejection of electron from metal is 330 nm, then work function for the photoelectric emission is :₀)

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1. In excited H atom, when electron drop from n = 4, 5, 6 to n = 1, there is emission of :

(A) UV light (B) Visible light (C) IR light (D) Radio waves

2. The wave mechanical model of an atom is based upon which of the following equations?

(A) Schrodinger’s equation (B) de Broglie’s equation

(C) Heisenberg’ uncertainity principle (D) All the above

3. For a given principal level n = 4, the energy of its subshells is for the order :

(A) s < d < f < p (B) s < p < d < f

(C) d < f < p < s (D) s < p < f < d

4. How many unpaired electrons are there in Ni2+?

(A) 0 (B) 2 (C) 4 (D) 8

5. Any p orbital can accommodate up to :

(A) Four electrons (B) Two electrons with parallel spin

(C) Six electrons (D) Two electrons with opposite spin

6. The ratio of energy of photon of  2000 Åto that of  4000 Åis :

(A) 2 (B) 1/4 (C) 4 (D) 1/2

7. If r is radius of first orbit, the radius of nth orbit of the H atom will be :

(A) r n2 (B) r n (C) r/n (D) r2n2

8. At 200 C , hydrogen molecules have velocity 2.4 10 cm s 5 1.The de Broglie wavelength in this case is approximately.

(A) 1Å (B) 1000 Å (C) 100 Å (D) 10 Å

9. The radius of second Bohr’s orbit is :

(A) 0.053 nm (B) 0.053nm

4 (C) 0.053 × 4 nm (D) 0.053 × 20 nm

10. The set of quantum numbers not applicable to an electron :

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1. The number of spectral lines obtained in Bohr spectrum of hydrogen atom when an electron is excited from ground level to 5th orbit is :

(A) 10 (B) 5 (C) 8 (D) 15

Paragraph for Q.2 - 5

A neutral atom of an element has 2K, 8L, 9M; and 2N electrons.

2. The atomic number of element is :

(A) 20 (B) 21 (C) 22 (D) 23

3. The total number of s electrons are :

(A) 8 (B) 6 (C) 4 (D) 10

4. The total number of p-electrons are :

(A) 6 (B) 12 (C) 18 (D) 24

5. The total number of d-electrons are :

(A) 1 (B) 2 (C) 3 (D) 4

6. The radius of the second Bohr orbit for Li2+ is :

(A) 0.529 4Å 3  (B) 0.529 2Å 3  (C) 0.529 4Å 9  (D) 0.529 2Å 3 

7. If velocity of an electron in 1st orbit of H atom is V, what will be the velocity in 3rd orbit of Li2+?

(A) V (B) V

3 (C) 3V (D) 9V

8. The spectral line obtained when an electron jumps from n = 6 to n = 2 level in hydrogen atom belongs to the :

(A) Balmer series (B) Lyman series (C) Paschen sereis (D) Pfund series

9. The ionisation potential of hydrogen atom is 13.6 eV. The energy required to remove an electron in the n = 2 state of the hydrogen atom is :

(A) 3.4 eV (B) 6.8 eV (C) 13.6 eV (D) 27.2 eV

10. The wavelength associated with a golf ball weighing 200 g and moving at a speed of 5 m h1is of the order :

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1. The correct set of quantum numbers for the unpaired electron of chlorine atom is :

n l m1 n l m1

(A) 2 1 0 (B) 2 1 1

(C) 3 1 1 (D) 3 0 0

2. The ratio of the energy of a photon of 2000 Åwavelength radiation to that of 4000 Åradiation is :

(A) 1/4 (B) 4 (C) 1/2 (D) 2

3. The radius of an atomic nucleus is of the order of :

(A) 1010cm (B) 1013cm (C) 1015cm (D) 108 cm

4. The e/m ratio for electron was determined by……..

(A) Einstein (B) Newton (C) J J. Thomson (D) Planck

5. In the third energy level, there are ………. Orbitals :

(A) 9 (B) 8 (C) 7 (D) 6

6. Naand Neare ….to each other :

(A) Isobar (B) Isoelectronic (C) Isotone (D) Isotope

7. When there are two electrons in the same orbital, they have……spins.

(A) Parallel (B) Symmetric (C) Antiparallel (D) None of these

8. The angular momentum of an electron in Bohr orbits is given as…….

(A) n h 2    _   (B) 3 n 2    _   (C) h n 5    _   (D) None of these

9. The filling of degenerate orbitals by electrons is governed by……….rule :

(A) Hund’s (B) Aufbau (C) Pauli’s (D) None of these

10. The maximum number of electrons in a orbitals, is governed by……..principle.