Radiation
Definition and meaning of Radiation in chemistry.
Radiation is the emission and continuous propagation of energy through space or a material medium in the physical form of waves or subatomic particles. In the context of physical chemistry, it most often refers to high energy electromagnetic radiation or the fast moving particles emitted during the spontaneous decay of unstable atomic nuclei.
In more detail
Electromagnetic radiation encompasses a remarkably broad spectrum, ranging from low energy radio waves to highly energetic gamma rays, and fundamentally involves mutually oscillating electric and magnetic fields. Particulate radiation consists of fast moving subatomic particles with distinct mass, such as alpha particles, beta particles, or free neutrons. High energy radiation, commonly known as ionizing radiation, possesses more than enough kinetic energy to completely remove tightly bound electrons from neutral atoms, thereby creating highly reactive ions. This intense ionization can easily initiate complex chemical reactions, violently break strong covalent chemical bonds, and cause significant structural damage to critical biological molecules like DNA and cellular proteins.
Key facts
| Field | Physical Chemistry |
|---|---|
| Common Forms | Electromagnetic continuous waves and discrete subatomic particles |
| Ionizing Property | High energy radiation can forcefully create reactive ions |
The high energy ultraviolet radiation constantly emitted from the sun has sufficient energy to quickly break the strong double bonds in oxygen molecules, leading directly to the necessary formation of ozone (O3) high in the Earth's stratosphere.
Frequently asked questions
What is the primary difference between ionizing and non-ionizing radiation?
Ionizing radiation has enough energy to detach electrons from atoms or molecules, whereas non-ionizing radiation only has enough energy to temporarily excite electrons to higher energy states or induce molecular vibrations.