X-rays: Definition, Waves, Spectrum, Real-world Applications, Energy

X-rays: We all have heard the X-rays in hospitals. A doctor recommends X-rays reports for an injured leg or any other injury. But what is an X-ray? How is it done? Is it harmful to our bodies or not? In recent times, the doctors recommended CT scans to the patients of COVID-\(19\) to determine the extent of damage in the lungs to treat the patient effectively. X-rays play a vital role in the medical treatment of several diseases.

Let us read the given article to understand the X-rays.

Electromagnetic Waves

Waves are disturbances that propagate from one place to the other, carrying momentum and energy. Based on the requirement of medium for propagation, waves can be classified as:

1. Electromagnetic waves: Waves that do not require a medium to propagate are classified as electromagnetic waves. Examples of electromagnetic waves are as follows: light waves, radio waves, infrared waves, X-rays, etc.
2. Mechanical waves: Waves that require a medium to propagate are classified as mechanical waves. Examples of mechanical waves are as follows: sound waves, waves formed in a string, waves formed on the surface of the water.

Thus X-rays belong in the category of electromagnetic waves, and it doesn’t require medium to propagate.

Electromagnetic Spectrum

The electromagnetic spectrum is the representation of different waves arranged in the order of their wavelength. In the above figure, we see that the different electromagnetic behaves are arranged in increasing wavelength from right to left. It is interesting to note that the highly energetic gamma rays, which are harmful to humans, to the visible light and the colours of the rainbow, to the radio waves which are present everywhere in the surroundings, belong to this category of electromagnetic waves.

All electromagnetic waves satisfy the following equation,

\(\lambda=\frac{c}{f}\)

Where,

 \((f)\) is the frequency of the electromagnetic wave.

\((λ)\) is the wavelength of the electromagnetic wave

\(f=\frac{E}{h}\)

\(E=\frac{h c}{\lambda}\)

Where

\(c=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\) represents the speed of light in a vacuum

\(h=6.626 \times 10^{-34} \mathrm{~J} . \mathrm{s}\) represents Planck’s constant.

What are X-Rays?

X-rays are a type of highly energetic electromagnetic wave that lies between ultraviolet rays and gamma rays. It possesses greater energy than ultraviolet rays but less energy than gamma rays. Its wavelength ranges \(0.01\) to \(10\) nanometres corresponding to the frequency range \(10^{16}\) to \(10^{20}\) Hertz.

Production: X-rays are produced in X-ray tubes when the electrons accelerated through a potential difference is directed onto a target, generally a metal. Generally, the metal used is tungsten. When the electron collides with a metal surface, it gets accelerated and transfers the energy to the atoms of the metal. Most of the energy is converted into heat, and very less percentage off it gets converted into X-rays.

Moseley’s Law

Henry Moseley used the add make model to determine the energy released when an electron is transferred between the Orbits in an atom. It was observed that energy released depends on the atomic number of the atom. Therefore, the X-ray obtained from different materials depends on the atomic number of the material. This can be used to determine the atomic number of any substance.

According to Moseley’s law, the frequency of the X-ray emitted by the element of atomic number \(Z\) is given by,

\(f=2.48 \times 10^{15}(Z-1)^{2} \mathrm{~Hz}\)

Here,

\(Z\) is the atomic number of the element

Applications of X-Rays

Medical Field: X-rays are high-energy beams that travel through the air and pass through the body of a patient, but the intensity varies with the varying density of the tissues, organs, fats, and bones. The skin, organs have lesser density, therefore, they are unable to block the X-rays, while the bones or kidney stones or tumours have greater density and can block the X-rays to some extent. The X-rays passing through the body are absorbed by the metal film, and depending on the intensity of the X-rays, the imprint is analyzed to determine any irregularities in the inside of the patient.

CT scan uses X-rays to determine the amount of damage that has occurred in the lungs by covid.

In Security: We all have encountered X-ray scanners in airports or metros that are used to scan our luggage. X-rays reveal what is inside of the baggage without the need to open it, it can detect metals and explosives or any suspicious objects. So, authorities can be alarmed for manual checks, and required actions can be taken. 

In Industries: X-rays can be used to detect the quality of industrial products or in construction. X-rays can be used to determine any deformity or an air gap.

Summary

Waves are disturbances that propagate from one place to the other, carrying momentum and energy. Waves can be categorised in mainly two categories:

1. Mechanical waves: Waves that require the medium to propagate. Example: sound
2. Electromagnetic waves: Waves that do not require the medium to propagate. Example: light, X-rays

The electromagnetic spectrum is the representation of the different electromagnetic waves in order of increasing or decreasing wavelength. X-rays are energetic waves. They have more frequency than ultraviolet rays and less frequency than gamma rays.

X-rays are produced by the transition of an electron in a metal atom due to energy transferred due to the collision of an energized electron. Each metal will produce an X-ray with a unique wavelength and frequency, and this principle was used by Henry Moseley to derive Moseley’s law. X-rays have a variety of uses in our lives. X-rays are used for medical diagnosis and in the checking of luggage at airports and metros.

Learn All About Radioactive Spectrum

Frequently Asked Questions (FAQs)

Q.1. What are waves?
Ans: Waves are disturbances that propagate through space and transfers momentum and energy from one place to the other. Example: sound, light.

Q.2. What are X-rays?
Ans: X-rays are a type of electromagnetic waves whose wavelength ranges \(0.01\) to \(10\) nanometres corresponding to the frequency range \(10^{16}\) to \(10^{20}\) Hertz.

Q.3. How do the X-rays propagate and how can they be represented?
Ans: X-rays move as oscillating electric and magnetic fields in space. All electromagnetic waves move as an oscillating electric and magnetic field.

Q.4. Is X-ray harmful to the human body?
Ans: Yes, X-rays are harmful to the human body and when X-rays are used for medical diagnosis, it is done with a lot of care and precaution as long exposure to highly energetic X-rays can cause damage to the tissues and muscles.

Q.5. How can X-rays produce?
Ans: X-rays are produced in X-ray tubes when the electrons accelerated through a potential difference is directed onto a target generally a metal. Due to this collision, the energy is transferred to the metal and the electron present in the metal undergoes a transition and due to this, energy is released in the form of X-rays.

Q.6. How can we represent X-ray waves with an equation?
Ans: X-ray waves can be represented as,
\(E=E_{0} \sin (\omega t-k x)\)
Where,
\(E_{0}\) is the amplitude of the oscillating electric field.
\(\omega\) is the angular frequency of the electromagnetic field.
\(t\) is the time instance of the electromagnetic field.
\(k\) is the wavenumber of the electromagnetic field.
\(x\) is the position of the point where the disturbance or the electric field is to be determined.

Q.7. What are other types of electromagnetic waves?
Ans: X-rays belong to the category of electromagnetic waves; other than the X-rays we also have the following waves in the electromagnetic spectrum.
1. Gamma waves
These are the most energetic waves in the electromagnetic spectrum. These waves have the highest frequency and the shortest wavelength. This wave is highly dangerous for living matter, and it can be used to kill cancer cells, tumours, bacteria, and viruses.
2. Ultraviolet waves
These waves are less energetic than gamma waves and X-rays, but they are still fatal for living beings. Long exposure to these waves can cause various diseases, including cancer. The frequency of these waves lies between \(400 \mathrm{~nm}-1 \mathrm{~nm}\). It is used in some water purifiers to kill the harmful bacteria and viruses in the water.
3. Visible waves
These waves can be perceived by the human eyes, and the rainbow we see is part of this visible spectrum of electromagnetic waves. Its frequency ranges in \(4 \times 10^{14} \mathrm{~Hz}-7 \times 10^{14} \mathrm{~Hz}\) and the wavelength range in \(400 \mathrm{~nm}-700 \mathrm{~nm}\). All the illuminating devices such as LEDs, tube-light, sun produce this wave.
4. Infrared waves
These waves transfer heat and are therefore also known as heatwaves. These waves are used in night vision cameras as they can identify the temperature of the bodies and can represent humans or machines working due to the difference in the temperature from the surrounding.
5. Microwaves
These waves lie in the lower frequency zone in the electromagnetic spectrum. These waves are used in microwave ovens as they can synchronize with the natural frequency of the water molecules and transfer energy to them, increasing the temperature of the food.
6. Radio waves
These waves are produced by an electrical circuit and can be used for communication purposes. These waves have the least frequency and the longest wavelengths larger than \(0.1 \,\text {m}\).

We hope this detailed article on X-rays helped you in your studies. If you have any doubts, queries or suggestions regarding this article, feel to ask us in the comment section and we will be more than happy to assist you. Happy learning!