The emission of one α-particle decreases the mass number by 4 whereas the emission of β - particles has no effect on mass number.
Net decrease in mass number = 222 – 214 = 8.
This decrease is only due to α-particle.
Hence,
Number of α-particle emitted = 8/4 = 2
Now,
The emission of one α-particle decreases the atomic number by 2 and one β-particle emission increases it by 1.
The net decrease in atomic number = 86 – 84 = 2
The emission of 2 α-particles causes decrease in atomic number by 4.
However,
The actual decrease is only 2.
It means atomic number increases by 2.
This increase is due to emission of 2 β-particles.
Thus,
2α and 2β-particles are emitted.
[Note : The above question is modified to include the final decay product so as to determine the number of α-particles and β-particles emitted in the process.
Here,
The final decay product is assumed to be Po-214.]
