Atoms Class 12 MCQ Questions: In the 19th century, various evidence came up that supported the atomic hypothesis of matter. J. J. Thomson's 1897 experiments on electric discharge through gases unveiled electrons as common, negatively charged constituents within atoms of various elements. This model depicted atoms as having uniformly distributed positive charges and embedded electrons, as of seeds in a watermelon, termed the “plum pudding model”. Ernst Rutherford, a student of Thomson, explored alpha particles from radioactive elements and proposed an experiment involving their scattering by atoms to probe atomic structure. This experiment was conducted in 1911 by Hans Geiger and Ernst Marsden, leading to Rutherford's planetary model (nuclear model) of the atom. This model suggested a central nucleus housing most of the atom's mass and positive charge, around which electrons orbited akin to planets around the sun. Despite its significance, Rutherford's model couldn't explain the discrete wavelengths of emitted light. This laid the groundwork for modern atomic understanding. In this chapter, Rutherford’s model, Bohr’s model, Atomic spectra, etc is discussed. In this article, we will go through the MCQs from Chapter 12 Atoms of CBSE Class 12 Physics for board exam 2024 preparation.
Atoms Class 12 MCQ Questions with Answers
Also, check:
1 The angular momentum of electrons in an atom produces
(a) magnetic moment
(b) Zeeman effect
(c) light
(d) nuclear fission
Answer: (a)
2 Which of the following series in the spectrum of hydrogen atom lies in the visible region of the electromagnetic spectrum?
(a) Paschen series
(b) Balmer series
(c) Lyman series
(d) Brackett series
Answer: (b)
3 According to Bohr’s theory of H atom, an electron can revolve around a proton indefinitely, if its path is
(a) a perfect circle of any radius
(b) a circle of an allowed radius
(c) a circle of constantly decreasing radius
(d) an ellipse with fixed focus
Answer: (b)
4 As an electron makes a transition from an excited state to the ground state of a hydrogen – like atom/ion
(a) kinetic energy decreases, potential energy increases but total energy remains same
(b) kinetic energy and total energy decrease but potential energy increases
(c) its kinetic energy increases but potential energy and total energy decrease
(d) kinetic energy, potential energy and total energy decrease
Answer: (c)
5 Bohr’s atom model is the modification of Rutherford’s atom model by the application of
(a) newton’s theory
(b) huygen’s theory
(c) maxwell’s theory
(d) planck’s quantum theory
Answer: (d)
6 In a hydrogen atom, which of the following electronic transitions would involve the maximum energy change
(a) n = 2 to n = 1
(b) n = 3 to n = 1
(c) n = 4 to n = 2
(d) n = 3 to n = 2
Answer: (b)
7 The shortest wavelength in Balmer’s series for Hydrogen atom is …A… and this is obtained by substituting …B … in Balmer’s formula. Here, A and B refer to
(a) 656.3 nm, n = 3
(b) 486.1 nm, n = 4
(c) 410.2 nm, n = 5
(d) 364.6 nm, n = ∞
Answer: (d)
8 According to Bohr’s model of hydrogen atom
(a) the linear velocity of the electron is quantised.
(b) the angular velocity of the electron is quantised.
(c) the linear momentum of the electron is quantised.
(d) the angular momentum of the electron is quantised.
Answer: (d)
9 The electrons of Rutherford’s model would be expected to lose energy because, they
(a) move randomly
(b) jump on nucleus
(c) radiate electromagnetic waves
(d) escape from the atom
Answer: (c)
10 Electrons in the atom are held to the nucleus by
(a) coulomb’s force
(b) nuclear force
(c) vander waal’s force
(d) gravitational force
Answer: (a)
Related:
Comments
All Comments (0)
Join the conversation