We know that energy from the sun is received in the form of radiation. Radiation is a form of energy that travels as waves or particles. There are many types of energy seen around the world. In this session let us know in detail about what is radiation, types of radiation, and radiation pressure.

Radiation can be described as energy or particles from a source that travels through space or other mediums. Light, heat, microwaves and wireless communications are all forms of radiation. This includes the following:

• Gravitational Radiation: such as radiation that takes the form of gravitational waves, or ripples in the curvature of space-time.
• Acoustic Radiation: such as ultrasound, sound, and seismic waves.

Radiation is often categorized into two types depending on the energy of the radiated particles.

• Ionizing Radiation – Ionizing radiation carries more than 10 eV, which is enough to ionize atoms and molecules and break chemical bonds.The ionizing radiation consists of alpha particles, beta particles, and gamma rays.
• Non-ionizing Radiation – Ionization is not caused by these radiations. They usually emit heat, which can sometimes be so intense as to result in burns. Visible light and infrared radiation are examples of non-ionizing radiation that may be seen by humans.

Nuclear radiation is an energy that is released by elementary particles of the atomic nucleus that are caused by the process of nuclear decay. According to the International Atomic Energy Agency, nuclear radiation can cause consequences to nature, human life and facility significantly. However, nuclear radiation could be both beneficial or harmful depending upon its utilization.

Alpha radiation is a heavy and very short-range particle. It is actually an ejected helium nucleus. Alpha radiation is another name for the alpha particles emitted in the type of radioactive decay called alpha decay. Alpha particles are helium-4 (4He) nuclei.

They are classified into two categories: Beta-minus (β) and Beta-plus (β+).

The Beta-minus radiation consists of an energetic electron. It is more penetrating than alpha radiation but less than gamma. While, the Beta-plus radiation is the emission of positrons, which are the antimatter form of electrons.

The Gamma rays or Gamma radiation consists of photons with a wavelength less than
3×10−11metres. The emission is a nuclear process that occurs to rid an unstable nucleus of excess energy after most nuclear reactions.

It is a form of electromagnetic radiation. The x-rays are powerful waves of electromagnetic energy. Most X-rays have a wavelength ranging from 0.01 to 10 nanometres, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 100 eV to 100 keV.

## Top 15 Most Important and Expected Questions on Nuclei in Hindi.

It is the pressure exerted by the electromagnetic radiation on the surface. It is defined as the mechanical pressure applied upon any surface due to the exchange of momentum between the object and the electromagnetic field. Radiation pressure on any surface depends on the nature of the surface and intensity of light used.
Radiation Pressure is given by the formula,

$$\begin{array}{l}P_{R}=\frac{(1+\alpha)I}{c}\end{array}$$

where α is the coefficient of reflection of the surface.
For a completely reflecting surface, α = 1.
For a completely reflecting surface, α = 0.
The radiation pressure is independent of the wavelength of incident light and depends on the nature of the surface on which light falls.

See the video below, to have a clear idea about heat transfer, and radiation.

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## Frequently Asked Questions – FAQs

### What are the types of nuclear radiation?

The following are the types of nuclear radiation: