An atom has 7 electrons in its M- shell and contains 18 neutrons in its nucleus. What is its mass number ?

1)25

2)27

3)35

4)43


  • : 532
  • : 6
    Previous Next

    35

    Suggest other answer
    Login to Discuss/suggest the answer...

  • Exam: Atomic Structure QUESTIONS





    Correct Answer to this question is 25 as the mass number is the sum of neutron and proton in the atom and in this case number of proton = number of electron that is 7 and number of neutrons are 18. Which means that the mass number of the atom is equal to 18+7=25.


  • : 0

    Close(X)
    Subscribe here for free mock test on IAS PCS SSC and other competitive exam. Signup here to get SSC CGL Solution and main exam study material