When a substance decays by alpha radiation,the mass number of the nucleus ________ and the atomic number ________.
A)increases by 4,increases by 2
B)reduces by 4,reduces by 2
C)increases by 2,increases by 4
D)reduces by 2,reduces by 4

Question

Quizplus · Accepted Answer

Alpha decay involves the emission of an alpha particle which is a helium nucleus consisting of two protons and two neutrons. Therefore, the mass number decreases by 4 (since the alpha particle has a mass of 4) and the atomic number decreases by 2 (since the nucleus loses two protons).

When a Substance Decays by Alpha Radiation,the Mass Number of the Nucleus