Answer: a) Tl (Thallium)
b) [tex]^{210}_{84}\textrm{Bi}\rightarrow ^{206}_{82}\textrm{Pb}+^4_2\textrm{He}[/tex]
[tex]^{218}_{84}\textrm{Bi}\rightarrow ^{214}_{82}\textrm{Pb}+^4_2\textrm{He}[/tex]
[tex]^{214}_{84}\textrm{Bi}\rightarrow ^{210}_{82}\textrm{X}+^4_2\textrm{He}[/tex]
Explanation:
Alpha decay : When a larger nuclei decays into smaller nuclei by releasing alpha particle. In this process, the mass number and atomic number is reduced by 4 and 2 units respectively.
General representation of an element is given as: [tex]_Z^A\textrm{X}[/tex]
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Total mass on reactant side = total mass on product side
214= A + 4 , A = 210
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
83= Z + 2, Z = 81
[tex]^{214}_{83}\textrm{Bi}\rightarrow ^{A}_{Z}\textrm{X}+^4_2\textrm{He}[/tex]
b)
1. [tex]^{210}_{84}\textrm{Bi}\rightarrow ^{206}_{82}\textrm{Pb}+^4_2\textrm{He}[/tex]
Total mass on reactant side = total mass on product side
210= A + 4 , A = 206
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
84= Z + 2, Z = 82
2. [tex]^{218}_{84}\textrm{Bi}\rightarrow ^{214}_{82}\textrm{Pb}+^4_2\textrm{He}[/tex]
Total mass on reactant side = total mass on product side
218= A + 4 , A = 214
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
84= Z + 2, Z = 82
3. [tex]^{214}_{84}\textrm{Bi}\rightarrow ^{210}_{82}\textrm{X}+^4_2\textrm{He}[/tex]
Total mass on reactant side = total mass on product side
214= A + 4 , A = 210
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
84= Z + 2, Z = 82
