Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert

Consider the following statements:
A. Atoms of each element emit characteristics spectrum.
B. According to Bohr's Postulate, an electron in a hydrogen atom revolves in a certain stationary orbit.

C. The density of nuclear matter depends on the size of the nucleus.
D. A free neutron is stable but a free proton decay is possible.
E. Radioactivity is an indication of the instability of nuclei. Choose the correct answer from the options given below.

PhysicsNuclear PhysicsJEE MainJEE Main 2021 (27 Jul Shift 2)
Options:
  • A A, B, C, D and E
  • B A, B and E only.
  • C B and D only
  • D A,C and E only
Solution:
1254 Upvotes Verified Answer
The correct answer is: A, B and E only.

(A) True, an atom of each element emits a characteristic spectrum.

(B) True, according to Bohr's postulates mvr=nh2π and hence electron resides into orbits of specific radius called stationary orbits.

(C) False, the density of the nucleus is constant.

(D) False, A free neutron is unstable decays into proton and electron and antineutrino.

(E) True unstable nucleus show radioactivity.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.