Radioactive decay is a fundamental nuclear process that helps us understand how unstable atomic nuclei transform to achieve greater stability. This article explores the various types of radioactive decay and their unique characteristics.
Understanding Nuclear Stability
An atom's nucleus contains protons and neutrons, collectively called nucleons. The stability of a nucleus depends on the ratio of neutrons to protons. When this ratio is outside the optimal range, the nucleus becomes unstable and undergoes radioactive decay.
Types of Radioactive Decay
Alpha (α) Decay
Alpha decay occurs when an unstable nucleus emits an alpha particle (24He), which consists of two protons and two neutrons. During this process:
The atomic number (Z) decreases by 2
The mass number (A) decreases by 4
The decay equation follows the format:
ZAX→Z−2A−4Y+24He
Beta (β) Decay
Beta decay exists in two forms: beta-minus (β⁻) and beta-plus (β⁺) decay.
Beta-Minus Decay
In β⁻ decay:
A neutron converts to a proton
An electron (β⁻) and an antineutrino (νˉ) are emitted
The atomic number increases by 1
The mass number remains constant
ZAX→Z+1AY+β−+νˉ
Beta-Plus Decay
In β⁺ decay:
A proton converts to a neutron
A positron (β⁺) and a neutrino (ν) are emitted
The atomic number decreases by 1
The mass number remains constant
ZAX→Z−1AY+β++ν
Gamma (γ) Decay
Gamma decay involves:
Emission of high-energy electromagnetic radiation
No change in atomic number or mass number
Usually occurs after alpha or beta decay
Nucleus transitions from excited state to ground state
ZAX∗→ZAX+γ