Nepedia
Back to Discover
Fluent Reader
⚛️

Uranium

physical science Maturity 11-13 Next article →

Uranium is a silvery-grey metal found in nature. It is part of the actinide series on the periodic table. This element has the atomic number 92. It is a very heavy and dense material. In fact, it is 70% denser than lead. It is only slightly less dense than gold or tungsten.

Pichblende
Pichblende

You can find it in small amounts in soil, rock, and water. It is often pulled from minerals like uraninite.

Uranium-hexafluoride-2D-V2
Uranium-hexafluoride-2D-V2

Uranium works in a very special way because it is radioactive. This means it undergoes radioactive decay. During this process, it usually emits an alpha particle. Different versions, called isotopes, decay at different speeds. The half-life for these isotopes ranges from 159,200 years to 4.5 billion years.

Evolution of Earth's radiogenic heat
Evolution of Earth's radiogenic heat

Scientists use these different speeds to find the age of the Earth. This is called radiometric dating.

Nuclear fission
Nuclear fission

People have been studying this metal for a long time. Martin Heinrich Klaproth discovered uranium in 1789. He found it in a mineral called pitchblende. He named it after the planet Uranus.

Uranus Voyager2 color calibrated
Uranus Voyager2 color calibrated

Later, Eugène-Melchior Péligot was the first to isolate the metal. In 1896, Henri Becquerel discovered its radioactive properties.

Becquerel plate
Becquerel plate

Later, researchers like Otto Hahn and Lise Meitner studied how it splits apart. This discovery changed how we use energy.

There are two main types of uranium found on Earth. Most of it is uranium-238, which makes up over 99% of natural uranium. It has 146 neutrons. The other main type is uranium-235. It has 143 neutrons and is very important.

Uranium-235 is fissile, which means it can split easily. When it splits, it creates a nuclear chain reaction. This reaction releases a lot of heat.

UraniumCubesLarge
UraniumCubesLarge

This heat is used to make electricity in power plants. It can also be used to make weapons like Little Boy.

Atomic cloud over Hiroshima - NARA 542192 - Edit
Atomic cloud over Hiroshima - NARA 542192 - Edit

Uranium connects to many things in our daily lives. Some people use uranium to make colorful pottery glazes.

Uranium ceramic - Flickr - Sencer Sarı
Uranium ceramic - Flickr - Sencer Sarı

You might even see uranium glass that glows bright green under UV light.

U glass with black light
U glass with black light

In the military, people use depleted uranium for heavy armor. Its high density helps it stop radiation or pierce through targets.

30mm DU slug
30mm DU slug

Even though it is a powerful tool, we must handle it carefully. Spent fuel becomes radioactive waste that needs to be managed safely.

376 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (25)
File:Nuclear fission.svg
Nuclear fission.svg
File:30mm DU slug.jpg
30mm DU slug.jpg
File:U glass with black light.jpg
U glass with black light.jpg
File:Uranium ceramic - Flickr - Sencer Sarı.jpg
Uranium ceramic - Flickr - Sencer Sarı.jpg
File:Vacuum capacitor with uranium glass.jpg
Vacuum capacitor with uranium glass.jpg
File:Uranus_Voyager2_color_calibrated.png
Uranus_Voyager2_color_calibrated.png
File:Becquerel plate.jpg
Becquerel plate.jpg
File:UraniumCubesLarge.jpg
UraniumCubesLarge.jpg
File:Atomic cloud over Hiroshima - NARA 542192 - Edit.jpg
Atomic cloud over Hiroshima - NARA 542192...
File:First four nuclear lit bulbs.jpeg
First four nuclear lit bulbs.jpeg
File:US and USSR nuclear stockpiles.svg
US and USSR nuclear stockpiles.svg
File:Pichblende.jpg
Pichblende.jpg

+ 13 more

More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.