General Science

ATOM AND NUCLEI MCQs

Total Questions : 20

Page 1 of 2 pages
Question 1. What is the energy needed to ionize H-atom from its second excited state if the energy of the ground state of H-atom is 13
  1.    3.4 eV
  2.    1.51 eV
  3.    12.1 eV
  4.    13.6 eV
 Discuss Question
Answer is Option B. -> 1.51 eV
Question 2. How many numbers of spectral lines are observed when hydrogen atoms are excited from ground state to the state of principal quantum number 4?
  1.    2
  2.    3
  3.    5
  4.    6
 Discuss Question
Answer is Option D. -> 6
Question 3. The velocity of an electron in the inner most orbit of an atom is
  1.    highest
  2.    lowest
  3.    mean
  4.    zero
 Discuss Question
Answer is Option A. -> highest
Question 4. Atoms and Nuclei Class 12 MCQ Question 1
  1.    increases
  2.    decreases
  3.    remains unchanged.
  4.    may increase or decrease depending upon the nucleus.
 Discuss Question
Answer is Option B. -> decreases
Question 5. An electron emitted in beta radiation originates from
  1.    inner orbits of atom
  2.    free electrons existing in the nuclei
  3.    decay of a neutron in a nuclei
  4.    photon escaping from the nucleus
 Discuss Question
Answer is Option C. -> decay of a neutron in a nuclei
Question 6. When a radioactive nucleus emits a (β-particle, the mass number of the atom:
  1.    decreases by four.
  2.    decreases by one.
  3.    remains the same.
  4.    increases by one.
 Discuss Question
Answer is Option C. -> remains the same.
Question 7. When a nucleus in an atom undergoes a radioactive decay, the electronic energy levels of the atom
  1.    do not change for any type of radioactivity.
  2.    change for α-radioactivity but not for others.
  3.    change for β-radioactivity but not for others.
  4.    change for α and β radioactivity but not for γ-radioactivity.
 Discuss Question
Answer is Option D. -> change for α and β radioactivity but not for γ-radioactivity.
Question 8. Which of the following statements is true about Bohr’s atomic model?
  1.    The electron can only move in particular orbits only
  2.    An electron radiates energy only when it jumps to another orbit
  3.    An atom consists of a positively charged nucleus
  4.    All of the above
 Discuss Question
Answer is Option D. -> All of the above
Question 9. γ-rays are originated from
  1.    nucleus.
  2.    outermost shell of nucleus.
  3.    innermost shell of nucleus.
  4.    outermost shell of atom.
 Discuss Question
Answer is Option A. -> nucleus.
Question 10. If an atom's atomic number is given by Z, its atomic mass by A, and its neutron number by N, which of the following is correct?
  1.    N = A + Z
  2.    N = Z - A
  3.    N = A - Z
  4.    None of the above is correct.
 Discuss Question
Answer is Option C. -> N = A - Z