We all love sunlight. Ever thought about how sunrays reach to us? It is through radiation. Sun rays travel through space and reach out to us. Radiation is defined as emission and transmission of energy from one source to receiver, in the form of waves or particles, through space, vacuum or any material medium.
CATEGORIES OF RADIATION
Radiation can be classified into two types – ionizing or non-ionizing radiation. An atom that has any charge is called an ion. Ionization is a process in which an atom either loses an electron or gains an electron. If it loses an electron, it becomes positively charged and if it gains an electron it becomes negatively charged. Ionizing radiations are radiations which have sufficient energy to lose electrons from atom. In Non-ionizing radiations the energy is not sufficient to lose electrons from the atom.
CAUSES OF RADIATION
The biggest source of light is sun. In sun two hydrogen atoms combine with each other to form an helium atom. This process is called nuclear fusion and as part of this large amount of energy is evolved. This energy is an electromagnetic radiation which is produced by the stars. The light we see is a type of non-ionized radiation. Non-ionized radiations are generally lower energy range electromagnetic radiation, as they don’t have enough energy to lose electrons. In everyday life, we see bulb, which is source of light for use. In this, tungsten filament is surrounded by inert gas and electricity is passed through tungsten filament. The electrons in filament are in constant collision with tungsten atoms, which causes vibration in atoms. This vibration is the source of light and heat in the form of radiation.
In a radioactive decay, the unstable atoms try to become stable by splitting into multiple stable atoms and in the process releasing large amount of energy. The radiations released as part of this are ionized radiations as they have large amount of energy. The most common types of decay are –
- Alpha decay – In this an atom releases energy by releasing two neutrons and two protons, which is the configuration of an Helium atom.
- Beta decay – In this the atom releases an electron or positron.
- Gamma decay – In this the atom does not release any sub atomic particle but rather tries to release energy by rearranging the existing particles.