Have you ever thought about a substance so loaded with energy that had the same explosive effect as 20 million pounds of TNT? Now, imagine this material also to be a source of power that could be used, even in the present state of knowledge, to supply humanity's energy needs long after the world's resources of conventional fuels such as coal and petroleum have become exhausted. Adding to it is the materials, strange combinations of properties. Sometimes the material is as hard and brittle as window glass, and at the same time, it could be as soft and plastic as a lead. This material is called Plutonium. There must be some questions in your mind like, what is Plutonium? How is Pu element formed and produced? What are its properties? We will now try to answer all these questions one by one.

What is Plutonium?

Plutonium, also known as Pu element, is considered as the first human-made element to be produced in large enough amounts. It is a heavy metallic element (more than twice as dense as iron). When freshly prepared, its uncorroded surface has a bright, silvery appearance. While most metals are good conductors of electricity and heat, Plutonium is not. Its electrical conductivity (ability to conduct electricity) and its thermal conductivity (ability to conduct heat) are both exceptionally low.

(Image to be added soon)

The image shows the position of the Pu element in the atomic table, where the Plutonium atomic number is 94.

Plutonium is a radioactive element that is not found in nature. Plutonium atomic number is 94, and its position in the Periodic Table shows that it is the sixth member in the series of elements called the "actinides," of which actinium, atomic number 89, is the first member. Plutonium is also one of the "trans-uranium" elements since it has an atomic number higher than that of uranium (number 92).

Plutonium Symbol


Plutonium Atomic Number


Atomic Mass

224 g.mol-1

Plutonium Electron Configuration

[Rn] 5f67s2

Physical Properties of Plutonium

Perhaps the most unusual physical property of Plutonium is its occurrence in six different crystal structure forms or allotropes, each in a specific, well-defined temperature range. It is not uncommon for elements to have more than one allotrope, but Plutonium is the only one with as many as six. 


Crystal Structure

Density (g/cm3)

Temperature Range (°C)


Simple monoclinic


21 to 104


Body-centered monoclinic


93 to 190


Face-centered orthorhombic


210 to 310


Face-centered cubic


320 to 440


Body-centered tetragonal


452 to 480


Body-centered cubic


490 to 550

Chemical Properties of Plutonium

Plutonium is a highly reactive metal. It readily combines with oxygen to form plutonium dioxide (PUO2). Increasing the temperature of Plutonium exposed to ordinary air rapidly increases the oxidation rate. Therefore, the metal must be protected in some manner when it is heated. 

State at 20°C


ChemSpider ID


Melting point of Plutonium

640°C, 1184°F, 913 K

Boiling point of Plutonium

3228°C, 5842°F, 3501 K

Density (g cm−3)

11.71 at 20°C

Relative atomic mass


Key isotopes

238Pu, 239Pu, 240Pu

CAS number


Now that you are familiar with the Pu element, we will look at some Plutonium uses.

Applications of Plutonium

When it comes to this element, plutonium uses are very limited. Only two out of the five isotopes have specific applications. The Plutonium uses include, producing energy on earth and in space, and nuclear weapons. Some of the general Plutonium uses are as follows.

  • It acts as a source of energy to produce electricity.

  • It is used in nuclear reactors, where it is used as fuels.

  • It acts as a neutron source to calibrate neutron detection equipment.

  • Plutonium has been used as a threshold detector for determining neutron energies.

Certain Facts About Plutonium

  • During the second world war, Plutonium was used to make the nuclear bomb called “Fat Man”, which was used to bomb Nagasaki. The bomb nearly claimed the lives of 80000 people.

  • Under certain conditions, Plutonium pyrophoricity gives it a glowing ember look.

  • Plutonium is used to produce around one-third of the total energy produced in a nuclear power plant.

  • For deep space missions, Plutonium is used as a vital source of power.

  • The Primary fuel used in neutron reactors is Plutonium.

  • The half-life of Plutonium-244 is about 82 million years.

  • Plutonium emits gamma rays, neutrons, and beta particles.

FAQ (Frequently Asked Questions)

1. How is Plutonium Made?

You cannot find Plutonium in nature. It is a human-made element. It is made from Uranium-238. When Uranium atoms absorb neutrons in a nuclear reactor, Plutonium gets produced. So, when Uranium-238 is placed in neutron radiation, it takes hold of a neutron; hence it becomes Uranium-239. Due to this it soon undergoes two β- decays. In the first reaction, the first β- decay converts the Uranium-239 to Neptunium-239, and the second β- decay converts the Neptunium-239 to Plutonium-239.

What is The Difference Between Plutonium And Uranium?

Plutonium is a radioactive element that is not found in nature. It was first made in 1941. It is entirely human-made. Although it is a bright silvery-white metal, it rapidly tarnishes in air to a dull grey. Uranium is a metal that is slightly radioactive and was discovered in 1789. It is silvery-white and corrodes to a black oxide in air. It is a naturally occurring element that is usually used in nuclear reactors. It is also used to make armor-piercing projectiles.