Question

What type of particle is emitted when U92238 decays to Th90234?

Select the correct answer below:

α particle

β particle

γ particle

positron

Answer 1

Answer: α particle

Explanation:-

A nuclear fission reaction is defined as the reaction in which a heavy nucleus splits into small nuclei along with release of energy.

The given reaction is

`^(238)_(92)\textrm{U}\rightarrow ^(234)_(90)\textrm {Th}+ ^(A)_(Z)\textrm{X}`

Now, as the mass on both reactant and product side must be equal:

To calculate A:

Total mass on reactant side = total mass on product side

238 = 234 + A

A = 4

To calculate Z:

Total atomic number on reactant side = total atomic number on product side

92 = 90 + Z

Z = 2

The particle with atomic number of 2 and mass number of 4 is
`\alpha` particle.

`^(238)_(92)\textrm{U}\rightarrow ^(234)_(90)\textrm {Th}+ ^(4)_(2){\alpha}`