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Radiation is a sort of energy that comes from somewhere and travels through matter or space. Light and heat are both examples of radiation. Because it has enough energy to take an electron from an atom and change it into an ion.
Properties of radiation:
Radiation can be absorbed by substances along its path. For example, alpha radiation travels only a few centimetres in air, beta radiation travels tens of centimetres in air, and gamma radiation travels over hundreds of centimetres in air.
Alpha radiation:
The least penetrating radiation is alpha. A human hand has the ability to halt (or absorb) it.
Beta radiation:
Beta radiation is capable of penetrating both air and paper. A thin layer of aluminium can be used to halt it.
Gamma radiation:
The most penetrating type of radiation is gamma. Air, paper, and thin metal can all be penetrated at low levels. Only many centimetres of lead or many metres of concrete can stop higher levels.
Varied forms of radiation have different penetrative characteristics.
Radiation Intensity:
The quantity of energy emitted per unit solid angle by per unit area of the radiating surface is known as radiation intensity.
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The intensity of radiation is also known as the radiation intensity.
SI system:
As a result, the radiation intensity unit is,
Dual Nature of Matter and Radiation:
The Dual Nature of Matter and Radiation, as its name implies, is concerned with the duality in the nature of matter, specifically particle nature and wave nature. Various experiments were carried out by various scientists to prove it. Light, for example, can act as both a wave and a particle. If you look at phenomena like interference, diffraction, or reflection, you’ll notice that light acts like a wave. When it comes to phenomena like the photoelectric effect, light, on the other hand, behaves like a particle.
Emission of Electrons:
The free electrons can be supplied with the lowest energy required to emit an electron from a metal’s surface using one of the techniques listed below:
Thermionic Emission: The required thermal energy is delivered to the free electrons by appropriately heating the metal to allow them to exit.
Field Emission: To emit an electron out of a metal, electrons are kept under the intense influence of an electric field.
Photo-electric Emission: Electrons are emitted from a metal surface when it is illuminated by the light of a suitable frequency. Photoelectrons are electrons that are created by light.
Photoelectric Effect:
The photoelectric effect is a phenomenon in which electrons escape from a material’s surface. The material’s surface is usually made up of both positive and negative ions. When light is incident on a metal surface, some of the electrons near the surface absorb enough energy from the incident radiation to overcome the pull of the positive ions. Furthermore, after the electrons have accumulated enough energy, they will escape from the metal surface and into the surrounding vacuum. The Photoelectric Effect is founded on this.
Laws of the photoelectric effect:
1. The photoelectric current is exactly proportional to the intensity of incident light for a particular metal and the frequency of incident light.
2. For each metal, there is a minimum frequency, known as the Threshold frequency, below which no photo-electric emission occurs.
3. The frequency of incident light affects the maximal kinetic energy of photoelectrons over a threshold frequency.
4. Photoelectric emission is a process that occurs in a split second.
Radiation hazards:
Ionizing radiation has enough energy to destroy the genetic material of live cells by affecting their atoms (DNA). Fortunately, our bodies’ cells are incredibly effective at mending the damage. A cell, on the other hand, may die or grow malignant if the injury is not treated properly.
Acute health effects such as skin burns and acute radiation syndrome (“radiation sickness”) can result from exposure to extremely high doses of radiation, such as being near to an atomic detonation. It can also have long-term health consequences, such as cancer and heart problems. Low-level radiation exposure in the environment has no immediate consequences on our health, but it does contribute to our overall cancer risk.
Conclusion:
There is no sensory reaction to ionising radiation exposure. Ionizing radiation, like radio waves, cannot be seen, felt, tasted, or smelled in normal doses. Only radiation detectors, such as Geiger-Mueller counters, film badges, and liquid scintillation counters, can detect it.
Ionizing radiation has the ability to permeate tissue. The type (e.g. gamma, x-ray, beta, neutron, alpha) and energy of radiation affect its capacity to penetrate.
