What are the different types of radioactive decay?

What is radio active decay?

Radioactive Decay:

A stable nucleus of an element has the correct balance of protons and neutrons.
Isotopes of an element which have too few or too many neutrons are usually unstable.
Carbon-12 is stable but carbon-14 which has 2 extra neutrons is unstable. Nitrogen-14 is stable but its isotope, nitrogen-13 which has 1 neutron less is unstable.
An unstable nucleus emits radiation in the form of an alpha particle, a beta particle or gamma rays to become a more stable nucleus.
Radioactive decay is the process in which an unstable nucleus changes into a more stable nucleus by emitting radiation.
In radioactive decay, the parent nuclide. emits radiation and changes into a daughter nuclide.
Radioactive decay is named after the type of radiation emitted.

People also ask

There are three types of radioactive decay:
(a) Alpha decay
(b) Beta decay
(c) Gamma decay

In alpha decay, the unstable parent nuclide emits an alpha particle.
Heavier unstable nuclei are more likely to undergo alpha decay. A bismuth-211 (₈₃Bi²¹¹) nucleus is unstable and emits an alpha particle. Lawrencium-257 (₁₀₃Lr²⁵⁷) also emits alpha particles.
Figure shows a diagrammatic representation of the decay of bismuth-211.
The equation for the decay of bismuth-211 is as follows:
The daughter nuclide has 2 protons less and 2 neutrons less than the parent nuclide. This means that in alpha decay, the proton number is reduced by 2 while the nucleon number is reduced by 4.
The general equation for alpha decay can be written as:

In beta decay, the parent nuclide emits a beta particle.
Usually heavier unstable nuclei with an excess of neutrons will undergo beta decay.
(a) Carbon-12 is stable but a carbon-14 (₆C¹⁴) nucleus is unstable and emits a beta particle.
(b) Silicon-28 is stable but silicon-31 (₁₄Si³¹) with three extra neutrons will emit a beta particle.
During beta decay, one of the neutrons changes into a proton and an electron, as shown by the equation below.
The proton remains in the nucleus while the electron is emitted as a beta particle.
This means that in beta decay, the nucleus loses a neutron but gains a proton.
Figure shows a diagrammatic representation of the decay of silicon-31.
The equation for the decay of silicon-31 is as follows:
The proton number increases by one because of the new proton formed but the nucleon number is unchanged because of the loss of one neutron.
The general equation for beta decay can be written as:
Other examples of nuclides which undergo beta decay are phosphorus-32, strontium-90, iodine-131 and actinium-228.

In gamma decay, a nucleus in an excited state (higher energy state) emits a γ-ray photon to change to a lower energy
state.
There is no change in the proton number and nucleon number.
A cobalt-60 nucleus in the excited state emits a y-ray photon. The equation for the decay is:
The (*) denotes the nucleus is in an excited state.
The general equation for gamma decay can be written as:
The emission of γ-rays often accompany the emission of α-particles and β-particles. The following are some examples of these decays.

Sometimes the daughter nuclide of a radioactive decay is still unstable. It will eventually decay into another nuclide which is also unstable.
This process continues as a radioactive decay series until a stable nuclide is reached. Each decay will emit either an a-particle or a β-particle and may be accompanied by γ-rays.
Polonium-218 goes through a series of seven decays to become a stable lead-206 atom, as shown in Figure. Three a-particles and four β-particles are emitted in the process.
If the initial and final nuclide of a decay series is given, the number of a-particles and β-particles emitted can be determined from the change in the nucleon number and proton number. The steps involved are:

Therefore, 6 alpha particles and 2 beta particles are emitted.
A radioactive decay series can be shown on a graph of nucleon number against proton number. Figure shows part of a decay series.

State the type of decay and balance the equation.

Solution:
Nuclide ₈₃Bi²⁰⁶ undergoes a series of decays to become ₈₂Pb²⁰⁶. Determine the number of alpha particles and beta particles emitted in this decay series.
Solution:

Therefore, 2 alpha particles and 3 beta perticles are emitted.