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 an

Step-by-step solution

( A ) True, an atom of each element emits a characteristic spectrum. ( B ) True, according to Bohr's postulates m v r = n h 2 π 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.