Question 1. in the following equation for the alpha decay of bismuth-214, supply the missing element that correctly completes the equation.
question 2. complete the following equations by correctly matching the appropriate product.

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

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

the answer is c.the valence of the atoms combine .