Atomic Structure- 4

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94. If r is the radius of first orbit, the radius of nth orbit of the hydrogen atom will be :
(A) rn2 (B) rn
(C) r/n (D) r2n2
Ans. (A)

95. When a metal is heated in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light, which we can observe in
(A) Raman spectra
(B) Absorption spectra
(C) Emission spectra
(D) Fluorescence
Ans. (C)

96. Bohr’s concept of the orbit in an atom was contradicted by
(A) De-broglie relationship
(B) Uncertainty principle
(C) Plancks hypothesis
(D) Hunds rule
Ans. (B)

97. The total energy of revolving electron in an atom
(A) Cannot be negative
(B) Can have any value above zero
(C) Can never be positive
(D) Will always be positive
Ans. (C)

98. The spectrum of helium is expected to be similar to that of:
(A) H
(B) Na
(C) He+
(D) Li+
Ans. (D)

99. When an electron drops from a higher energy level to a low energy level then:
(A) Energy is absorbed
(B) Energy is emitted
(C) Atomic number increases
(D) Atomic number decreases
Ans. (B)

100. In Lyman series an electron jumps from higher energy level to
(A) K energy level
(B) M energy level
(C) N energy level
(D) L energy level
Ans. (A)

101. In which region of electromagnetic spectrum does the Lyman series of hydrogen atom lie?
(A) X-Ray
(B) Ultraviolet Ray
(C) Visible
(D) Infrared
Ans. (B)

102. The total number of orbitals in a principal shell are:
(A) n
(B) n²
(C) 2n²
(D) 3n²
Ans. (B)

103. The mercury and sodium street lamps light up because of–
(A) Atomic absorption
(B) Electron absorption
(C) Atomic emission
(D) Electron emission
Ans. (C)

104. The atomic orbital is—
(A) The Circular path of the electron
(B) Elliptical shaped orbit
(C) Three dimensional field around nucleus
(D) The region in which there is maximum probability of finding electron
Ans. (D)

105. Which of the following atoms has a nonspherical outermost orbital.
(A) H
(B) Li
(C) Be
(D) B
Ans. (D)

106. Orientation of atomic orbital is controlled by –
(A) Principal Quantum number
(B) Magnetic Quantum number
(C) Electron spin quantum number
(D) Azimuthal Quantum number
Ans. (B)

107. Two electrons in an orbital are differentiated by which of the following?
(A) Magnetic quantum number
(B) Spin quantum number
(C) Principal quantum number
(D) Azimuthal quantum number
Ans. (B)

108. “All the four quantum numbers of two electrons in an atom are not the same.” It is the law of —
(A) Hund’s rule
(B) Pauli’s exclusion principle
(C) Uncertainty Principle of Heisenberg
(D) Avogadro’s Law
Ans. (B)

109. When there are two electrons in the same orbital, they have:
(A) Same spin
(B) Opposite spin
(C) Same or opposite spin
(D) No spin
Ans. (B)

110. Which orbital is dumb- bell shaped?
(A) s-orbital (B) p-orbital
(C) d-orbital (D) f-orbital
Ans. (B)

111. In an atom the order of filling up of the orbitals is governed by—
(A) Aufbau principle
(B) Heisenberg’s uncertainty principle
(C) Hund’s rule
(D) Pauli’s exclusion Principle
Ans. (A)

112. According to Aufbau principle, the correct order of energy of 3d, 4s and 4p orbitals is:
(A) 4p < 3d < 4s (B) 4s < 4p < 3d (C) 4s < 3d < 4p (D) 3d < 4s < 4p Ans. (C) 113. The statement that the electron occupies available orbital singly before pairing occurs is called (A) Einstein principle (B) Rutherford hypothesis (C) Pauli's exclusion principle (D) Hund's rule Ans. (D) 114. Nitrogen atom has unpaired electrons. This can be explained as due to: (A) Hund's rule (B) Aufbau Principle (C) Pauli's exclusion principle (D) Heisenberg’s uncertainty principle Ans. (A) 115. Number of neutrons in an atom of hydrogen is (A) One (B) Zero (C) Two (D) Three Ans. (B) [SSC CHSL 2014] 116. The subatomic particle that does not have any electric charge is a/an _____. (A) Electron (B) Proton (C) Neutron (D) All options are correct. Ans. (C) 117. How is atomic mass number determined? (A) By total number of protons (B) By total number of neutrons (C) By adding number of protons and neutrons (D) By total number of electrons Ans. (C) 118. What are the components of nucleus of an atom? (A) Only Protons (B) Protons and Neutrons (C) Neutrons and Electrons (D) Only Neutrons Ans. (B) 119. What is the mass of one mole of a substance in grams is called? (A) Nuclear Mass (B) Atomic Mass (C) Mass No. (D) Molecular Mass Ans. (D) 120. Which among the following is a negatively charged ion? (A) Calcium ion (B) Zinc ion (C) Silver ion (D) Iodine ion Ans. (D) 121. Atomic Number is denoted by which alphabet? (A) A (B) N (C) Z (D) E Ans. (C) 122. How are 'Cations' formed? (A) Addition of electron (B) Removal of electron (C) Addition of proton (D) Removal of proton Ans. (B) 123. How are 'anions' formed? (A) Addition of electron (B) Removal of electron (C) Addition of proton (D) Removal of proton Ans. (A) 124. Which amongst the following is not a Cation? (A) Aluminium ion (B) Copper ion (C) Sulphate ion (D) Zinc ion Ans. (C) 125. What are isobars? (A) Elements with same atomic number but different mass number (B) Elements with different atomic number but same mass number (C) Elements with different atomic number and different mass number (D) Elements with same atomic number and same mass number Ans. (B) 126. Anions are formed by _____. (A) Losing of electrons (B) Gaining of electrons (C) Gaining of neutrons (D) Losing of neutrons Ans. (B) 127. Who discovered Proton? (A) Ernest Rutherford (B) Friedrich Miescher (C) Goldstein (D) Henry Cavendish Ans. (C)

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