`._(90)^(234)Th` disintegrates to give `._(82)^(206)Pb` as the final product. How many alpha and beta particles are emitted in this process?

Explanation

`underset("Parent")(._(90)^(234)Th) to underset("End product")(._(82)^(206)Pb)`
Decrease in mass = (234 - 206) = 28
Mass of `alpha`-particle = 4
So, Number of `alpha` particles emitted `= (28)/(4) = 7`
No. of `beta` particles emitted `= 2 xx` No. of `alpha`particles - (At no of parent - At. No. of end product)
`= 2 xx - (90 - 82) = 6`