The electromagnetic spectrum includes all kinds of light, even the ones that human eyes cannot perceive. The lights that make up the rainbows are only a tiny portion of the electromagnetic spectrum. There are different types of rays that fall into the electromagnetic spectrum, such as- radio waves, microwaves, gamma rays, UV rays, and X-rays. All these lights that I just mentioned are invisible to human eyes. X-rays are part of the electromagnetic spectrum with a very particular wavelength. The wavelength of X-rays is between 0.01nm-10nm. The frequency range of X-rays lies between 30PHz to 30Ehz. The energy of X-rays ranges from 100eV to 100keV. X –rays are mostly used for their power to penetrate condense matters like human skin, bones, and flesh. In the medical department, an X-ray is one of the most common names that is used to get a better picture of the insides. X-ray has been first discovered by a German physicist, Wilhelm C Roentgen in 1895.
Different Types of Rays
The categorization of the electromagnetic waves is based on their wavelengths, frequencies, and energy levels. Though all of the electromagnetic waves travel at the speed of light in vacuum, they have variable wavelengths. In order of their ascending frequency and descending wavelengths, different types of rays can be sorted like this- radio waves, microwaves, infrared radiation, visible light, ultraviolet rays, X-rays, and gamma rays. Wavelengths ranging from one meter to one millimeter and frequency between 0.3GHz to 300GHz are called radio and microwaves. Infrared waves can be sorted into three categories i.e., near, short, mid, long, and far wavelength infrared. The wavelengths of these infrared rays are- near (0.75-1.4um), short (1.4-3um), mid (3-8um), long (8-15um), far (15-1000um). Electromagnetic radiation that has a wavelength between 400-700nm can be detected by the human eye and therefore called the visible light. Ultraviolet rays have their wavelength between 100-400nm. X-rays and gamma rays have a wavelength between 0.01 to 10 nm.
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Property of X-rays
X-ray photons carry an abundant amount of energy that is able to ionize atoms and disrupt the molecular bonds. X-ray has a shorter wavelength than that of the visible light. Hard X-rays can penetrate dense objects without getting much scattered. The penetration depth varies according to the magnitude of the x-ray spectrum..
Types of X-Rays
Based on energy level, there are different types of rays that fall into the x-ray domain- Hard X-rays and Soft X-rays.
Hard X-Rays- Energy between 5-10keV, wavelength below 0.1 nm
Soft X-Rays- Energy between 100eV-5keV, wavelength between 0.1nm-10nm.
Hard x-rays and gamma rays are often confused. The distinction is that gamma rays are produced from the nucleus of atoms, but the x-rays are produced from the electron of the atoms.
Uses of X-ray
As mentioned earlier, X-rays are heavily used in the medical domain as it can penetrate hard and condense matters like human skin, flesh, and bones. There are other uses as well such as
Broken Bones- X-rays are used to take photographs of broken bones of the human body.
Radiation Therapy- If a patient is diagnosed with cancer, the x-ray can be used for radiation therapy.
Airport Security- For the properties of an x-ray, in the airport, it is used to scan people and their baggage for security purposes.
Revealing Counterfeit Art- X-rays are also used to correctly infer the originality of paintings and architectures.
Solved Examples
1. Who First Discovered X-ray?
X-ray has been first discovered by a German physicist, Wilhelm C Roentgen in 1895.
2. What are the Different Types of Rays that Fall into the Domain of X-ray?
An X-ray can be classified into two types, Hard X-rays and soft x-rays.
Did You Know
X-ray has been first discovered by a German physicist, Wilhelm C Roentgen in 1895. X-ray enabled the scientists to dive deeper into the human DNA structure. Though mostly used in the medical domain, X-rays are used in other domains as well, such as airport security, archeology, etc. The ‘X’ in X-ray stands for the unknown as it stands in mathematics.
FAQs on Electromagnetic Spectrum X-rays
1. What are X-rays and where do they fit in the electromagnetic spectrum?
X-rays are a form of high-energy electromagnetic radiation. In the electromagnetic spectrum, they are located between ultraviolet (UV) rays and gamma rays. X-rays have very short wavelengths, typically ranging from 0.01 to 10 nanometres, and correspondingly high frequencies, which gives them significant energy and penetrating power.
2. What are the main properties of X-rays?
X-rays exhibit several key properties that make them useful in various fields. According to the CBSE Class 12 syllabus, the most important properties are:
- High Penetrating Power: They can pass through materials that are opaque to visible light, such as soft body tissues, but are absorbed by denser materials like bones and lead.
- Travel in Straight Lines: Like light, X-rays travel in straight lines and cannot be deflected by electric or magnetic fields, proving they are uncharged.
- Ionisation: They possess enough energy to ionise atoms and molecules in the matter they pass through.
- Photographic Effect: X-rays can expose photographic film, which is the principle behind medical radiography.
- Fluorescence: They cause certain materials, like barium platinocyanide, to glow or fluoresce.
3. What is the difference between hard and soft X-rays?
The distinction between hard and soft X-rays is based on their energy and penetrating ability:
- Hard X-rays: These have higher energy and shorter wavelengths. Due to their high energy, they have greater penetrating power and are used in applications like radiation therapy to destroy cancer cells and in industrial radiography to inspect metal parts.
- Soft X-rays: These have lower energy and longer wavelengths. Their penetration is lower, making them suitable for applications where deep penetration is not needed or desired, such as medical diagnostic imaging (radiography) to view bones without damaging surrounding tissues excessively.
4. What are some common applications of X-rays in medicine and industry?
X-rays have numerous critical applications, primarily in two sectors:
- In Medicine: They are widely used for diagnostic purposes, such as detecting bone fractures, identifying dental problems, and locating foreign objects in the body. Computed Tomography (CT) scans use X-rays to create detailed cross-sectional images. They are also used in radiotherapy to target and destroy cancerous tumours.
- In Industry and Security: X-rays are used to inspect welded joints for defects, analyse the crystal structure of materials (X-ray crystallography), and for security screening of baggage at airports. They are also used to authenticate artworks by revealing underlying layers of paint.
5. How are X-rays produced?
X-rays are typically produced in a device called an X-ray tube or Coolidge tube. The process involves accelerating electrons to a very high speed using a high-voltage potential difference. These high-energy electrons are then directed to strike a metal target, usually made of a heavy element like tungsten. When the electrons are suddenly stopped or decelerated by the target, their kinetic energy is converted into electromagnetic radiation, creating a continuous spectrum of X-rays known as Bremsstrahlung (braking radiation).
6. Why are X-rays considered ionising radiation and what precautions are necessary when using them?
X-rays are classified as ionising radiation because their high energy is sufficient to knock electrons out of the atoms and molecules of the material they pass through, including human tissue. This process creates charged ions and free radicals, which can damage or destroy living cells and DNA. Uncontrolled or excessive exposure can increase the risk of cancer. Therefore, strict safety precautions are essential, such as using lead shielding (aprons, screens), limiting the duration and intensity of exposure, and maintaining a safe distance from the X-ray source.
7. How do X-rays differ from gamma rays?
The primary difference between X-rays and gamma rays lies in their origin, not necessarily their energy, as their energy ranges can overlap. X-rays are generated by processes involving electrons outside the atomic nucleus, such as the deceleration of fast-moving electrons or when electrons transition between energy levels in an atom. In contrast, gamma rays originate from processes within the atomic nucleus, such as radioactive decay or nuclear reactions. This difference in origin is the fundamental distinction between the two types of radiation.
