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Radiation 101: Radiation What is Radiation in Electromagnetic Spectrum

In this The Science Fact blog we will discuss Radiation What is Radiation in Electromagnetic Spectrum? Radiation, what is it? Keep reading to learn all about radiation (radiation what is), the electromagnetic spectrum classification (radiation in electromagnetic spectrum), and types of radiation (ionizing and nonionizing radiation). Subscribe for daily fun facts about science, science on the web, and your source for fun facts about science. Stay informed.

Radiation what is

Radiation is a form of energy that can travel through space in the form of waves or particles. It is all around us, from the sun's rays to the microwaves in our kitchens. While most radiation poses no threat to our health, some types can be harmful at high doses. The risks associated with radiation exposure depend on the dose and type of radiation. To protect ourselves and the environment, different measures must be taken depending on the type of radiation and its intended use. Despite its potential risks, radiation also has many beneficial applications in fields such as medicine and energy production.

Classification of Radiation in Electromagnetic Spectrum

Radiation is a fundamental aspect of the universe, as everything emits it. Unlike other forms of energy transfer, radiation can travel through a vacuum, making it the primary way in which the Earth interacts with the rest of the cosmos. Each type of radiation has its own unique properties, such as energy, wavelength, and frequency, which determine its properties and potential uses. Although energy, wavelength, and frequency are distinct, they are mathematically related, meaning that knowledge of one can provide insight into the other two.

Radiation is most often classified based on its wavelength, which is the distance between wave crests. This is known as the Electromagnetic Radiation Spectrum. The size of the wavelengths can vary greatly, ranging from ultra-long radio waves to very short gamma rays. As the wavelength decreases, the energy of the wave increases. This means that electromagnetic waves with shorter wavelengths have more energy than those with longer wavelengths. By understanding the relationship between wavelength and energy, we can better understand the properties and effects of different types of radiation.

Radiation is all around us, but most of it is invisible to the human eye. The electromagnetic spectrum is divided into different sections based on wavelength, with radio waves having the longest wavelength and gamma rays having the shortest. Humans can only see a small portion of the spectrum, known as visible light, which is made up of different colors ranging from red to violet. Each color corresponds to a different wavelength, with red having the longest and violet having the shortest. While we may not be able to see all types of radiation, they play important roles in our daily lives, from radio waves used for communication to x-rays used in medical imaging.

Electromagnetic radiation comes in a range of wavelengths, from the incredibly small to the incredibly long. To put it in perspective, at the center of the Electromagnetic Spectrum we have Infrared Radiation, with one-micrometer wavelength (1 μm). This is equivalent to one millionth of a meter, which is about 1/100th the diameter of a human hair. Radiowaves have wavelengths up to 62 miles, while gamma ray wavelengths are the scale of a nucleus. It's important to keep in mind just how vast the range of electromagnetic radiation can be!

radiation in electromagnetic spectrum (radiation what is)
radiation in electromagnetic spectrum

Radio waves

Radio waves are a type of electromagnetic radiation with wavelengths ranging from about one millimeter to 100 kilometers. These waves are used for communication, such as capturing radio signals from stations to listen to music or news. They are also emitted by celestial objects such as stars and gases in space, providing valuable information to astronomers studying the universe.

Radio wavelength ranges from the length of a baseball bat to the width of Yellowstone National Park.


Microwave radiation has a wavelength ranging from about one millimeter to one meter, making it shorter than radio waves but longer than infrared radiation. This type of radiation is commonly used in household appliances such as microwaves to cook food quickly, but it also has important applications in astronomy. Astronomers use microwave radiation to study the structure and composition of nearby galaxies, providing valuable insights into the universe around us.

Microwaves are around one centimeter long, the length of a staple.


Infrared waves have a variety of uses, from night vision technology to space exploration. One of the most common applications of infrared technology is in night vision goggles, which detect the infrared light emitted by objects with heat, including our own skin. In addition, scientists use infrared light to map the dust and gas between stars in space, providing valuable insights into the structure and composition of the universe. The wavelength of infrared light ranges from 700 nanometers to 1 millimeter, which is longer than visible light but shorter than radio waves.

The infrared wavelength is about the size of a sharp pencil tip.


The visible light wavelength range is the portion of the electromagnetic spectrum that can be detected by the human eye. This range includes the colors of the rainbow and is emitted by various sources such as fireflies, light bulbs, and stars. The wavelength of visible light ranges from approximately 400 to 700 nanometers (nm). The colors of visible light, in order from shortest to longest wavelength, are violet, blue, green, yellow, orange, and red.

The visible wavelength is about half the length of a bacteria.

visible spectrum of radiation what is radiation in electromagnetic spectrum
visible spectrum of electromagnetic radiation

Ultraviolet (UV)

Ultraviolet radiation is a type of electromagnetic radiation that has a shorter wavelength than visible light. It is emitted by the Sun and can cause skin damage and sunburns. In addition to being emitted by the Sun, UV radiation is also emitted by hot objects in space, such as stars and galaxies. The UV spectrum is divided into three ranges: UV-A, UV-B, and UV-C, with UV-C having the shortest wavelength and highest energy. The wavelength of UV light ranges from 10 nanometers to 400 nanometers. The shorter the wavelength, the more harmful the UV light can be to living organisms.

The UV wavelength is about the size of a virus.


X-rays have a very short wavelength and high energy, making them useful for imaging dense objects like teeth and for security purposes at airports. X-rays can penetrate through materials, making them useful in medical imaging. In addition, hot gases in the Universe emit X-rays, allowing scientists to study the properties of these gases and better understand the structure of the cosmos. The wavelength of x-ray radiation ranges from 0.01 to 10 nanometers (nm), which is shorter than the wavelength of visible light.

The x-ray wavelength is about the width of DNA.


Gamma radiation is a type of electromagnetic radiation that has the highest energy and shortest wavelength in the electromagnetic spectrum. It is produced by the decay of atomic nuclei and can be harmful to living organisms in large doses. However, gamma rays also have important uses in medicine, such as in gamma-ray imaging, which allows doctors to see inside the body without invasive procedures. Interestingly, the universe itself is the biggest generator of gamma radiation, with sources including supernovae, black holes, and gamma-ray bursts. Gamma radiation has the shortest wavelength in the electromagnetic spectrum, ranging from about 0.01 nanometers to 0.1 nanometers.

Gamma radiation wavelength is about the diameter of an atom’s nucleus.

Types of Radiation (Radiation what is a type of radiation)

Radiation can be classified into two main types: ionizing and non-ionizing radiation. Non-ionizing radiation, such as radio waves and microwaves, have lower energy and are generally considered less harmful. However, ionizing radiation, such as X-rays and gamma rays, have higher energy and can cause damage to living tissue.

To ensure the safe use of ionizing radiation, the International Atomic Energy Agency (IAEA) sets standards for protection of people and the environment. These standards aim to minimize the risks associated with the use of ionizing radiation in various applications.

Non-ionizing Radiation

Non-ionizing radiation refers to a type of radiation that lacks the energy required to remove electrons from atoms or molecules. While it may not be powerful enough to cause ionization, it can still produce heat by causing molecules to vibrate. This is how microwave ovens work. Other examples of non-ionizing radiation include radio waves and visible light. Visible light is a type of non-ionizing radiation that can be detected by the human eye, while radio waves are invisible to our senses but can be decoded by radios.

Risks of Non-Ionizing Radiation

Non-ionizing radiation, such as radio waves, microwaves, and visible light, is generally considered safe for most people. However, prolonged exposure to certain sources of non-ionizing radiation, such as ultraviolet (UV) radiation from the sun or high levels of radiofrequency (RF) radiation from cell phones, can increase the risk of skin cancer and other health problems. Workers who are regularly exposed to non-ionizing radiation, such as those in the telecommunications or medical industries, may need to take special precautions to protect themselves from the potential risks.

Ionizing Radiation

Ionizing radiation is a powerful form of energy that has the ability to strip electrons from atoms or molecules. This process, known as ionization, can cause significant changes at the atomic level when interacting with matter, including living organisms. The result is often the production of electrically charged particles called ions, which is why this type of radiation is referred to as "ionizing." It is important to note that exposure to ionizing radiation can have harmful effects on living cells and tissues, making it a significant concern in fields such as medicine and nuclear energy.

Risks of Ionizing Radiation

Ionizing radiation, when exposed to high doses, can be extremely harmful to our bodies, causing damage to cells and organs and even leading to death. However, when used correctly and in appropriate doses with necessary protective measures, ionizing radiation can have many beneficial uses, such as in energy production, industry, research, and medical diagnostics and treatment of diseases like cancer. It is every nation’s responsibility to regulate the use of radiation sources and provide radiation protection to protect workers, patients, the public, and the environment from potential harmful effects of ionizing radiation.

Sources of Ionizing Radiation

Ionizing radiation can come from a variety of sources, but one common origin is unstable atoms. These atoms, also known as radioactive atoms, are unable to hold their particles together due to an imbalanced composition of protons and neutrons in their nucleus. As they transition into a more stable state, they release energy in the form of ionizing radiation such as alpha particles, beta particles, gamma rays, or neutrons. While this type of radiation can be harnessed for various benefits, it is important to handle it safely due to its potential harmful effects. Most atoms on Earth are stable, thanks to a balanced and stable composition of particles in their nucleus.

Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting particles or waves. The most common types of radioactive decay are alpha decay, beta decay, gamma decay, and neutron decay. Each type of decay involves the release of different particles or waves, which can have varying levels of ionizing radiation.

Alpha Radiation

Alpha radiation is a type of radioactive decay in which heavy, positively charged particles are emitted from the nucleus of an atom. These particles are unable to penetrate the skin and can be stopped by a single sheet of paper. However, if alpha-emitting materials are ingested or inhaled, they can cause harm by exposing internal tissues directly.

Americium-241 is an example of an element that undergoes alpha decay and is commonly used in smoke detectors worldwide.

Beta Radiation

Beta radiation is a type of nuclear radiation where the nucleus releases electrons that are smaller and more penetrating than alpha particles. These electrons can pass through materials like water, but can be stopped by a few millimeters of aluminum.

Some examples of unstable atoms that emit beta radiation include tritium and carbon-14. Tritium is commonly used in emergency lighting to mark exits, as its beta radiation causes phosphor material to glow without the need for electricity. Carbon-14 is used to date objects from the past.

Gamma Rays

Gamma radiation is a type of electromagnetic radiation that is similar to X-rays. It has a variety of applications, including cancer treatment. While some gamma rays can pass through the human body without causing harm, others can be absorbed and cause damage. To reduce the risk of harm, thick walls made of concrete or lead can be used to block the intensity of gamma rays. This is why radiotherapy treatment rooms in hospitals for cancer patients have such thick walls.

The use of technetium-99 is an element that emits gamma rays. It is the most common radiopharmaceutical used in medical imaging.


Neutron radiation is a type of radiation that is caused by the interaction of neutrons with matter. Neutrons are uncharged particles that are found in the nucleus of an atom. When they collide with other atoms, they can cause the release of other types of radiation, such as alpha, beta, gamma, or X-rays. Neutrons are highly penetrating and can only be stopped by thick barriers made of materials such as concrete, water, or paraffin. Due to their ability to penetrate matter, neutron radiation can be particularly dangerous to living organisms.

Neutron radiation can be generated through various means, such as in nuclear reactors or through nuclear reactions triggered by high-energy particles in accelerator beams. These neutrons can then become a significant source of indirectly ionizing radiation, which can have harmful effects on living organisms.

Radiation Uses

  • Healthcare

  • Energy

  • Environment

  • Climate Change

  • Industry

  • Science

  • Engineering

  • Technology

Radiation is a versatile tool that has a wide range of applications across various fields. In the field of health, radiation is used for cancer treatments and diagnostic imaging methods. Radiation also plays a crucial role in the production of electricity through solar and nuclear energy. Additionally, radiation can be used to treat wastewater and create new plant varieties that are resistant to climate change, making it an important tool in environmental and climate change efforts. In industry and science, nuclear techniques based on radiation are used to examine objects from the past and produce materials with superior characteristics, such as in the car industry.

Radiation protection

Radiation is a crucial tool in the medical field, allowing for life-saving cancer treatments and diagnostic imaging. However, it is important to recognize the potential risks associated with its use and take appropriate measures to protect both people and the environment. Non-ionizing radiation, which has lower energy levels, may require less protective measures than ionizing radiation, which has higher energy levels.

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