Study of radioactive decay of unstable nuclei resulting in emission of a particle lead us to four different observations listed below:
(A) no change in atomic number and mass number.
(B) no change in mass number but the atomic number decreases by 1.
(C) no change in mass number but the atomic number increases by 1.
(D) atomic number decreases by 2 and the mass number decreases by 4.
Arrange the particles emitted in the above four cases in correct sequence.
Choose the correct answer from the options given below.
1
alpha particle, positron, electron, photon.
2
alpha particle, electron, positron, photon.
3
photon, positron, electron, alpha particle.
4
alpha particle, positron, photon, electron.