Answer: a) Tl (Thallium)
b)
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:
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
b)
1.
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.
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.
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
Answer:
Rb: [Kr] 5s
Step-by-step explanation:
Rb is element 37, the first element in Period 5.
It has one valence electron, so its valence electron configuration is 5s.
The noble gas configuration uses the symbol of the previous noble gas as a shortcut for the electron configurations of the inner electrons.
The preceding noble gas is Kr, so the electron configuration is Rb: [Kr] 5s.
