Question

Find out number of alpha and beta particles emitted during the following disintegrations:-
(a) Thorium(atomic number 90 and mass number 232) -------> Lead(atomic number 82 and mass number 208).

(b) X( atomic number 90 and mass number 216) -------> Y(atomic number 86 and mass number 196)

Answer 1

Answer:

a)6 alpha and 4 beta

b)5 alpha and 6 beta

Explanation:

1. when alpha particle is emitted then the atomic mass no is decresed by 4 and atomic no is decresed by 2.
2. when beta particle is emitted then atomic no is incresed by 1 and atomic mass no remains same.
3. a)atomic mass no is decresed from 232 to 208 i.e. total decrement is 24.Therefore 6 alpha particles are emitted.atomic no is 90 after emission of 6 alpha particle it is 78.but here atomic no.is 82 i.e. emission of 4 beta particles takes place.
4. b)similarly 5 alpha and 6 beta particle are emitted