Promethium is a fascinating element that holds several intriguing facts. This article will delve into some interesting aspects of promethium, shedding light on its unique properties and applications.

One of the most captivating facts about promethium is its rarity. It is the only element in the periodic table that is exclusively radioactive and does not occur naturally.

This means that promethium can only be produced artificially in laboratories, making it a highly sought-after element for scientific research and various industrial purposes.

Another intriguing fact about promethium is its potential use in nuclear batteries. Due to its radioactive nature, promethium-147 emits beta radiation, which can be converted into electrical energy.

This characteristic makes Promethium a promising candidate for powering long-lasting, compact batteries that could be used in space exploration or remote locations where traditional power sources are not feasible.

Furthermore, promethium has found applications in medical science. Its radioactive isotopes, such as promethium-149, are used in cancer treatment to target and destroy cancer cells.

This targeted radiation therapy helps minimize damage to healthy tissues, making promethium a valuable tool in the fight against cancer.

Interesting Facts About Promethium

Interesting Facts About Promethium

The Elusive Element

Promethium is the only element in the periodic table that is exclusively radioactive, with no stable isotopes.

A Hidden Discovery

Promethium was first discovered in 1945 by scientists at the Oak Ridge National Laboratory in Tennessee.

A Rare Earth Element

Promethium is classified as a rare earth element, belonging to the lanthanide series on the periodic table.

Glowing in the Dark

Promethium emits a faint blue glow due to its radioactive decay, making it useful in self-powered luminous paint.

Short-Lived Isotopes

The most stable isotope of promethium, promethium-145, has a half-life of only 17.7 years.

Named After a Titan

Promethium is named after the Greek mythological figure Prometheus, who stole fire from the gods to benefit humanity.

Artificial Creation

Promethium is not found naturally on Earth and can only be produced through the bombardment of other elements in a nuclear reactor.

Radioactive Power Source

Promethium-147 is used in nuclear batteries to power spacecraft and other remote devices due to its long half-life.

Medical Applications

Promethium-149 is used in certain cancer treatments, emitting beta radiation to target and destroy cancer cells.

Challenging to Handle

Due to its radioactivity, promethium requires special handling and containment to prevent harm to humans and the environment.

Unusual Magnetic Properties

Promethium exhibits unique magnetic properties, including a high magnetic susceptibility and a Curie temperature of 830°C.

Exploring the Cosmos

Promethium has been detected in the spectra of certain stars, providing insights into the composition of distant celestial bodies.

Atomic Number 61

Promethium is the 61st element in the periodic table, with its atomic number representing the number of protons in its nucleus.

Radioactive Decay Series

Promethium-147 undergoes beta decay to form neodymium-147, which is stable and not radioactive.

Industrial Applications

Promethium compounds are used in specialized industrial applications, such as luminous dials, lasers, and phosphors.

Chasing the Blue Glow

Scientists continue to study and explore the unique properties of promethium, unlocking new potential applications and understanding its behavior.

Fun Facts About Promethium for Students and Kids

Interesting Facts About Promethium

1. Promethium is the only rare earth element that is radioactive.

Promethium is a unique element because it is the only one among the rare earth elements that is radioactive. This means that its atoms are unstable and can break down over time, releasing radiation.

2. It was named after the Greek mythological character Prometheus.

Promethium gets its name from Prometheus, a figure in Greek mythology who stole fire from the gods and gave it to humans. The element was named after him because it was discovered through the process of extracting and studying the radioactive properties of uranium.

3. Promethium has no stable isotopes.

Unlike many other elements, promethium does not have any stable isotopes. This means that all of its isotopes are radioactive and eventually decay into other elements over time.

4. It is used in nuclear batteries for spacecraft.

Promethium is used in the production of nuclear batteries, which are used to power spacecraft and satellites. These batteries rely on the radioactive decay of promethium to generate electricity for long-duration missions in space.

5. Promethium glows in the dark.

When promethium is exposed to air, it oxidizes and forms a compound that emits a faint blue glow. This property makes it useful in certain applications, such as in glow-in-the-dark paint and emergency exit signs.

6. It is extremely rare on Earth.

Promethium is one of the rarest elements on Earth. It is not naturally found in large quantities and is usually produced through the artificial bombardment of other elements in a nuclear reactor.

7. Promethium has medical applications.

Promethium-147, one of the isotopes of promethium, is used in certain medical devices for treating cancer. It emits beta radiation, which can be targeted at cancer cells to destroy them.

8. It was first discovered in 1945.

Promethium was first discovered in 1945 by scientists at the Oak Ridge National Laboratory in the United States. They were able to isolate and identify the element through the study of uranium fission products.

9. Promethium has a silvery-white appearance.

In its pure form, promethium has a silvery-white appearance. However, due to its rarity and radioactive nature, it is not commonly seen or used in everyday life.

10. It has a relatively short half-life.

The isotopes of promethium have relatively short half-lives, ranging from a few hours to a few years. This means that they decay and lose their radioactivity relatively quickly compared to other radioactive elements.

11. Promethium can be used to measure the thickness of materials.

Promethium-147 is often used in industrial applications to measure the thickness of materials, such as metal sheets. Its radioactive properties allow for precise measurements to be made.

12. It is not found in nature in significant amounts.

Promethium is not naturally occurring in significant amounts on Earth. It is mainly produced through the artificial synthesis of other elements or as a byproduct of nuclear reactions.

Most Common Uses of Promethium

1. Nuclear Batteries

Promethium-147, a radioactive isotope of Promethium, is commonly used in nuclear batteries. These batteries are compact and long-lasting, making them ideal for applications where a stable power source is required, such as in pacemakers, spacecraft, and remote sensing devices.

2. Thickness Gauges

Promethium-147 is also utilized in thickness gauges, which are used to measure the thickness of materials. The radioactive properties of Promethium-147 allow for accurate and reliable measurements, making it a valuable tool in industries such as manufacturing, construction, and quality control.

3. Light Sources

Promethium-147 is used in the production of self-luminous paint and signs. The radioactive decay of Promethium-147 emits beta particles, which excite phosphors and produce a steady glow. This property makes Promethium-147 an excellent choice for creating long-lasting, low-maintenance light sources.

4. X-ray Calibration

Promethium-147 is employed in the calibration of X-ray equipment. Its radioactive nature allows for precise calibration of X-ray machines, ensuring accurate and consistent imaging results. This is crucial in medical and industrial applications where precise measurements are essential.

5. Research and Development

Promethium is often used in research and development activities, particularly in the field of nuclear physics. Its unique properties and radioactive nature make it a valuable tool for studying atomic structure, radiation effects, and other scientific phenomena.

6. Radiography Testing

Promethium-147 is utilized in radiography testing, a non-destructive testing method used to inspect the internal structure of objects. By exposing the object to Promethium-147’s radiation and capturing the resulting image, flaws or defects within the object can be detected, making it useful in industries such as aerospace, automotive, and manufacturing.

7. Smoke Detectors

Promethium-147 is used in some types of smoke detectors. The radioactive decay of Promethium-147 generates ionizing radiation, which is detected by the smoke detector’s sensor. When smoke particles enter the detector, they disrupt the ionization process, triggering the alarm. This application ensures early detection of fires and enhances safety in residential and commercial buildings.

Chemistry of Promethium


Promethium, with the atomic number 61 and symbol Pm, is a rare earth element that was first discovered in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell at the Oak Ridge National Laboratory in Tennessee, United States.

They were studying the byproducts of uranium fission and identified a new element in the radioactive decay chain. The name “promethium” was derived from the Greek mythological character Prometheus, who stole fire from the gods and gave it to humans.


After its discovery, promethium was initially thought to be a member of the lanthanide series of elements. However, it was later found to have unique properties that distinguished it from other elements in the series.

Promethium is the only lanthanide that does not have any stable isotopes, making it highly radioactive and challenging to study. Due to its scarcity and limited applications, promethium has not played a significant role in history or industry.

Basic Chemistry

Promethium is a soft, silvery-white metal that is highly reactive and easily oxidizes in air. It has a melting point of 1,042 degrees Celsius and a boiling point of 2,460 degrees Celsius.

The element exhibits paramagnetic properties, meaning it is weakly attracted to magnetic fields. Promethium has a relatively high density and is denser than most other lanthanides. It is also a good conductor of electricity.

Chemical Properties

Promethium primarily exists in the +3 oxidation state, where it loses three electrons to form Pm3+ ions. These ions have a pink color, giving promethium salts a characteristic pink hue.

The element readily forms compounds with other elements, such as oxides, halides, and sulfides. Promethium compounds are generally soluble in water and exhibit similar chemical behavior to other lanthanides.


Due to its scarcity and radioactivity, promethium has limited practical applications. However, its radioactive isotopes, particularly promethium-147, have been used in various fields. Promethium-147 is a beta emitter and has been utilized in nuclear batteries, which power spacecraft and satellites.

It has also found applications in thickness gauges, luminous paint, and as a radiation source for research purposes. Despite its limited use, promethium continues to be of interest to scientists for its unique properties and potential future applications.

Interesting Physical Properties of Promethium

1. Radioactive Element

Promethium is a radioactive element, meaning it spontaneously emits radiation. It has no stable isotopes, and its most stable isotope, promethium-145, has a half-life of only 17.7 years.

This property makes promethium useful in various applications, such as in nuclear batteries and as a source of beta radiation for medical purposes.

2. Soft and Malleable

Promethium is a soft and malleable metal. It can be easily cut with a knife and shaped into different forms. However, due to its radioactivity, promethium is not commonly used in everyday applications and is primarily studied for its scientific and research purposes.

3. Silvery-White Appearance

Promethium has a silvery-white appearance, similar to other rare earth metals. It has a metallic luster and reflects light, giving it a shiny appearance. However, due to its rarity and limited commercial use, promethium is not commonly seen in its pure form.

4. High Melting and Boiling Points

Promethium has relatively high melting and boiling points compared to other rare earth metals. It melts at approximately 1,046 degrees Celsius (1,915 degrees Fahrenheit) and boils at around 3,000 degrees Celsius (5,432 degrees Fahrenheit). These high temperatures indicate the strong metallic bonding present in promethium.

5. Paramagnetic Behavior

Promethium exhibits paramagnetic behavior, meaning it is weakly attracted to magnetic fields. This property arises from the presence of unpaired electrons in its atomic structure. Promethium’s paramagnetic nature makes it useful in certain magnetic applications, such as in the production of magnetic alloys and materials.