Question
Question: How do you complete nuclear equations and describe its type of radiation?...
How do you complete nuclear equations and describe its type of radiation?
Solution
There are three types of radiation emitted during the radioactive decay which are named according to the first three letters of Greek alphabets. While writing the nuclear equation the atomic number on both sides of the equation should be the same.
Complete step by step answer:
In the radioactive decay, there are three types of emission which generally takes place, they are
(1) alpha particles
(2) beta particles’
(3) gamma particles
Alpha decay:
The process of nuclear disintegration which emits the alpha particles are known as alpha decay. Example of the nucleus which shows alpha decay is uranium-238.
The alpha decay is shown below.
92238U→24He+90234Th
Here, the uranium atom is transmuted to thorium atom and gives the alpha particles.
Beta decay:
Beta decay is the second type of emission which emits beta particles. The beta particles are the high energy electrons which are emitted by the nucleus.
Example: Thorium-234 undergoes beta decay
The beta decay is shown below.
90234Th→−10e+91234Pa
Gamma decay:
In the production of gamma rays all types of nuclear reaction takes place. In the alpha decay of U-238, two gamma rays are formed of different energies in addition with alpha particles.
The gamma decay is shown below.
92238U→24He+90234Th+200γ
While writing nuclear equations, some rules which need to be followed
(1) The sum of the mass numbers on the reactant side should be equal to the sum of the mass numbers on the product side.
(2) The atomic numbers on the two sides of the reaction should be equal.
In the alpha decay of 238U, both the atomic number and the mass number are conserved.
Mass number: 238 = 4 +234
Atomic number: 92= 2+ 90
For thorium -234
mass number: 234=0+234234=0+234
atomic number: 90=−1+9190=−1+91
The mass numbers of the original nucleus and the new nucleus are equal as a neutron has been lost, but a proton has been gained, and so the sum of protons and neutrons (mass number) remains the same. The atomic number in the reaction has been increased by one as the new nucleus has one more proton than the original nucleus. In the beta decay, a thorium-234 nucleus has one more proton than the original nucleus. In the beta decay, a thorium-234 nucleus changes to a protactinium-234 nucleus
Note: All the nuclear reaction emits gamma rays but they are generally not shown. As compared to the chemical reaction the nuclear reaction produces more amount of energy. The energy released by the nuclear reaction is around 1×1018kJ/mol.