Answer : The correct answer is Name = Thallium (Th) , atomic mass = 210 and atomic number = 81 .
Alpha decay :
When atomic nucleus emits an alpha particle that process is known as alpha particle decay . The symbol of alpha particle is [tex] ^4_2He [/tex] . where 4 is atomic mass ( 2 protons + 2 neutrons ) and 2 atomic number .
When alpha particle is released the resultant nuclei (daughter nuclei) have 4 less atomic mass and 2 less atomic number .
Example for nuclear equation of alpha decay can be expressed as:
[tex] {_{90}^{230}Th} \rightarrow {_2^4He} + {_{88}^{226}Ra} [/tex]
Given :
Radioisotope = Bi Atomic mass = 214 Atomic number = 83
When it will release alpha particle , atomic mass will be decreased by 4 and atomic number by 2 .
Atomic mass = 214 - 4 = 210 Atomic number = 83-2 = 81
The atom with atomic number 81 is Thallium (Th) . Hence the daughter nuclei so produced is [tex] ^2^1^0_8_1Th [/tex]
The nuclear reaction can be written as :
[tex] ^{214}_{83}Bi \rightarrow _2^4He + _{81}^{210}Th [/tex]
