Radiation
Definition and meaning of Radiation in chemistry.
Radiation is the emission and continuous propagation of energy through space or a material medium. This energy travels in the physical form of continuous waves or fast discrete subatomic particles. In physical chemistry, radiation usually refers to high energy electromagnetic waves or particles from decaying nuclei.
In more detail
Electromagnetic radiation encompasses a remarkably broad spectrum of different wavelengths and energy levels. This spectrum ranges from low energy radio waves up to highly energetic gamma rays. All electromagnetic radiation fundamentally involves mutually oscillating electric and magnetic fields traveling through space.
Particulate radiation consists of fast moving subatomic particles that possess distinct physical mass. Common examples of particulate radiation include alpha particles, beta particles, and free neutrons. High energy radiation is commonly known in chemistry and physics as ionizing radiation.
This specific type of radiation possesses more than enough kinetic energy to affect neutral atoms. It can completely remove tightly bound electrons from neutral atoms to create highly reactive ions. This intense ionization process can easily initiate complex and unexpected chemical reactions.
It can violently break strong covalent chemical bonds within various molecular structures. Ionizing radiation can also cause significant structural damage to critical biological molecules like DNA and proteins. Chemists must carefully shield their experiments and themselves when working with any radioactive materials.
Many analytical chemistry techniques rely heavily on different forms of controlled radiation. Spectroscopy uses specific wavelengths of light to identify unknown compounds in a laboratory sample. Scientists also use controlled radiation to sterilize medical equipment by destroying dangerous bacteria and viruses.
Key facts
| Field | Physical Chemistry |
|---|---|
| Common forms | Electromagnetic waves and subatomic particles |
| Key property | High energy radiation can forcefully create reactive ions |
| Electromagnetic examples | Radio waves, visible light, and gamma rays |
| Particulate examples | Alpha particles, beta particles, and free neutrons |
| Biological impact | Can break chemical bonds and damage DNA |
The high energy ultraviolet radiation constantly emitted from the sun affects our atmosphere. It has sufficient energy to quickly break the strong double bonds in oxygen molecules. This process leads directly to the necessary formation of ozone (O3) high in the stratosphere.
Frequently asked questions
What is the primary difference between ionizing and non-ionizing radiation?
Ionizing radiation has enough energy to detach electrons completely from neutral atoms or molecules. Non-ionizing radiation only has enough energy to temporarily excite electrons or induce harmless molecular vibrations.
Do all forms of chemical radiation possess physical mass?
No. Particulate radiation involves fast subatomic particles that have physical mass. Electromagnetic radiation consists of massless continuous waves of pure energy.
How does high energy radiation affect strong chemical bonds?
High energy radiation can transfer enough energy to a molecule to break its covalent bonds. This violent process creates highly reactive fragments called free radicals that trigger further unexpected chemical reactions.