Atomic Structure PYQs Set 13 (PDF)

Set 13 of 14 · Questions 361-390 of 415

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Atomic Structure · Set 13 (Q361-390)
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361. $The statement that is not correct is$ (1) $angular quantum number signifies the shape of the orbital$ (2) $energies of stationary states in hydrogen like atoms is inversely proportional to the square of the principal quantum number$ (3) $total number of nodes for 3 s orbital is three$ (4) $the radius of the first orbit of He^{+} is half that of the first orbit of hydrogen atom.$ 362. $Given below are two statements : Statement I: When an electric discharge is passed through gaseous hydrogen, the hydrogen molecules dissociate and the energetically excited hydrogen atoms produce electromagnetic radiation of discrete frequencies. Statement II: The frequency of second line of Balmer series obtained from He^{+} is equal to that of first line of Lyman series obtained from hydrogen atom. In the light of the above statements, choose the correct answer from the options given below :$ (1) $Statement I is false but Statement II is true$ (2) $Both Statement I and Statement II are true$ (3) $Statement I is true but Statement II is false$ (4) $Both Statement I and Statement II are false$ 363. $Given below are two statements. Statement I: According to Bohr's model of an atom, qualitatively the magnitude of velocity of electronincreases with decrease in positive charges on the nucleus as there is no strong hold on the electron by thenucleus. Statement II: According to Bohr's model of an atom, qualitatively the magnitude of velocity of electronincreases with decrease in principal quantum number. In the light of the above statements, choose the answer from the options given below:$ (1) $Both Statement I and Statement II are false$ (2) $Both Statement I and Statement II are true$ (3) $Statement I is false but Statement II is true$ (4) $Statement I is true but Statement II is false$ 364. $Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A: In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface. Reason R : When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place. In the light of the above statements, choose the most appropriate answer from the options given below :$ (1) $Both A and R are correct and R is the correct explanation of A$ (2) $A is correct but R is not correct$ (3) $Both A and R are correct but R is NOT the correct explanation of A$ (4) $A is not correct but R is correct$ 365. $Select the correct statements from the following. A. Atoms of all elements are composed of two fundamental particles. B. The mass of the electrons is 9.10939 \times 10^{- 31} kg . C. All the isotopes of a given element show same chemical properties. D. Protons and electrons are collectively known as nucleons. E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter. Choose the correct answer from the options given below.$ (1) $C, D and E$ (2) $A and E$ (3) $B, C and E$ (4) $A, B and C$ 366. $Identify the INCORRECT statements from the following:(A) Notation_{12}^{24} Mg represents 24 protons and 12 neutrons.(B) Wavelength of a radiation of frequency 4.5 \times 10^{15} s^{- 1} is 6.7 \times 10^{- 8} m .(C) One radiation has wavelength = λ_{1} (900 nm) and energy = E_{1} . Other radiation has wavelength = λ_{2} (300 nm) and energy = E_{2} . E_{1} : E_{2} = 3 : 1 .(D) Number of photons of light of wavelength 2000 pm that provides 1 J of energy is 1.006 \times 10^{16} . Choose the correct answer from the options given below:$ (1) $(B) and (C) Only$ (2) $(A) and (D) Only$ (3) $(A) and (C) Only$ (4) $(A) and (B) Only$ 367. $The isoelectronic set of ions is :$ (1) $N3-, O2-, F-and N a^{+}$ (2) $N^{3 -}, Li^{+}, Mg^{2 +} and O^{2 -}$ (3) $F-, Li+, Na+and M g^{2 +}$ (4) $L i^{+}, N a^{+}, O^{2 -} and F^{-}$ 368. $From the following energy levels of hydrogen atom, the values of E_{\infty} and E_{3} in J are, respectively______E_{\infty} = \dots \dots \dots \dots ._______E_{3} = \dots \dots \dots \dots ._______E_{2} = - 0.545 \times 10^{- 18} J_______E_{1} = - 2.18 \times 10^{- 18} J$ (1) $1, - 0.242 \times 10^{- 18}$ (2) $\infty, - 0.726 \times 10^{- 18}$ (3) $0, - 0.242 \times 10^{- 18}$ (4) $0, - 0.321 \times 10^{- 18}$ 369. $Select the correct statements from the following A. Atoms of all elements are composed of two fundamental particles. B. The mass of the electron is 9.10939 \times 10^{- 31} kg . C. All the isotopes of a given element show same chemical properties. D. Protons and electrons are collectively known as nucleons. E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter. Choose the correct answer from the options given below:$ (1) $B, C and E only$ (2) $A, B and C only$ (3) $C, D and E only$ (4) $A and E only$ 370. $P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness, dr, at a distance r from the nucleus. The volume of this shell is 4 p r^{2} dr. The qualitative sketch of the dependence of P on r is:$ (1) (2) (3) (4) 371. $The number of radial node/s for 3 p orbital is:$ (1) $1$ (2) $4$ (3) $2$ (4) $3$ 372. $Isochores are drawn at\dots\dots\dots\dots$ (1) $constant volume, pressure vs temperature$ (2) $constant pressure, volume vs temperature$ (3) $constant temperature, pressure vs volume$ (4) $constant temperature, volume vs temperature$ 373. $The region in the electromagnetic spectrum where the Balmar series lines appear is$ (1) $Microwave$ (2) $Ultraviolet$ (3) $Visible$ (4) $Infrared$ 374. $Aqueous solution of which salt will not contain ions with the electronic configuration 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} ?$ (1) $NaCl$ (2) $C a I_{2}$ (3) $NaF$ (4) $KBr$ 375. $In a given atom no two electrons can have the same values for all the four quantum numbers. This is called$ (1) $Hund’s Rule$ (2) $Aufbau principle$ (3) $Uncertainty principle$ (4) $Pauli’s Exclusion principle.$ 376. $The number of angular and radial nodes in 3 p orbital respectively are$ (1) $3,1$ (2) $1,1$ (3) $2,1$ (4) $2,3$ 377. $An ion has 18 electrons in the outermost shell, it is$ (1) $C u^{+}$ (2) $T h^{4 +}$ (3) $C s^{+}$ (4) $K^{+}$ 378. $The number of subshells associated with n = 4 and m = - 2 quantum numbers is$ (1) $2$ (2) $8$ (3) $4$ (4) $16$ 379. $A certain orbital has no angular nodes and two radial nodes. The orbital is:$ (1) $2 s$ (2) $3 s$ (3) $3 p$ (4) $2 p$ 380. $The number of spherical nodes in 3 p orbitals are/is$ (1) $one$ (2) $three$ (3) $none$ (4) $two$ 381. $Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?$ (1) $Lyman series$ (2) $Balmer series$ (3) $Paschen series$ (4) $Brackett series$ 382. $The spectrum of He is expected to be similar to that$ (1) $H$ (2) $L i^{+}$ (3) $Na$ (4) $H e^{+}$ 383. $Maximum number of electrons theoretically possible for an orbit with principal quantum number n = 6 in an atom is$ (1) $27$ (2) $98$ (3) $72$ (4) $50$ 384. $How many emission spectral lines are possible when hydrogen atom is excited to n^{th} energy level?$ (1) $\frac{n ( n + 1 )}{2}$ (2) $\frac{( n + 1 )}{2}$ (3) $\frac{( n - 1 ) n}{2}$ (4) $\frac{n ^{2}}{2}$ 385. $The following quantum numbers are possible for how many orbitals: n = 3, l = 2, m = + 2 ?$ (1) $1$ (2) $2$ (3) $3$ (4) $4$ 386. $Number of unpaired electrons in N^{2 +} i s / a r e$ (1) $2$ (2) $0$ (3) $1$ (4) $3$ 387. $Which of the following statements do not form a part of Bohr’s model of hydrogen atom?$ (1) $Energy of the electrons in the orbits are quantized.$ (2) $The electron in the orbit nearest the nucleus has the lowest energy.$ (3) $Electrons revolve in different orbits around the nucleus.$ (4) $The position and velocity of the electrons in the orbit cannot be determined simultaneously.$ 388. $Amongst the following statements, that which was not proposed by Dalton was :$ (1) $all the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass.$ (2) $chemical reactions involve reorganisation of atoms. These are neither created nor destroyed in a chemical reaction.$ (3) $when gases combine or reproduced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same T & P .$ (4) $matter consists of indivisible atoms.$ 389. $Which of the following statements are correct, if the threshold frequency of caesium is 5.16 \times 10^{14} Hz ?(A) When Cs is placed inside a vacuum chamber with an ammeter connected to it and yellow light is focused on Cs, the ammeter shows the presence of current.(B) When the brightness of the yellow light is dimmed, the value of the current in the ammeter is reduced.(C) When a red light is used instead of the yellow light, the current produced is higher with respect to the yellow light.(D) When a blue light is used, the ammeter shows the formation of current.(E) When a white light is used. the ammeter shows formation of current. Choose the correct answer from the options given below:$ (1) $B, C and D Only$ (2) $A, C, D and E Only$ (3) $A, B, D and E Only$ (4) $A, D and E Only$ 390. $The hydrogen spectrum consists of several spectral lines in Lyman series (L_{1}, L_{2}, L_{3} \dots; L_{1}) has lowest energy among Lyman series). Similarly it consists of several spectral lines in Balmer series (B_{1}, B_{2}, B_{3} \dots; B_{1} has lowest energy among Balmer lines). The energy of L_{1} is x times the energy of B_{1} . The value of x is____\times 10^{- 1} . (Nearest integer)$