View the periodic table of radioactive elements, and a list of each's most stable isotopes

Unusually stable, undiscovered elements may exist near atomic number 126

While heavier elements like uranium and plutonium are unstable and decay quickly, simulations suggest a pocket of stability exists for elements with approximately 126 protons and 184 neutrons. Such elements may have practical applications, such as americium, a synthetic element used in smoke detectors.

Astatine-211 is a radioisotope that can be used for therapeutic cancer treatment

With less than 30 grams in the Earth's crust at any given time, astatine is the rarest naturally occurring element. Its decay produces alpha particles that can damage diseased cells with the same impact as 10,000 electrons.

A list of five everyday products that rely on radioactivity, including exit signs and gemstones

Like some glow-in-the-dark wristwatches, some exit signs contain sealed tubes of tritium—radioactive hydrogen gas—which emit low-energy beta particles that react with surrounding elements to produce light, making them visible without batteries. In smoke detectors, smoke particles disrupt the steady flow of ions generated by americium-241.

How radioactive isotopes are created and used for medical diagnostics

In particle accelerators, protons can be accelerated into other atoms to create radioactive isotopes, which can be attached to specific molecules to create radiotracers that are taken up by specific cells. Radiotracers can emit particles that produce light once they collide with an electron, and this light can be captured by a PET scanner to diagnose specific ailments.

An overview of radioactivity, which can spontaneously change one element into another

Unstable atomic nuclei can transmute into a new element—an atom with a different number of protons—by emitting an alpha particle (two protons and two neutrons) or a beta particle (an electron). The electron can emerge from the nucleus when a neutron, which has no charge, suddenly transforms into a proton and an electron, thereby maintaining zero charge before and after the transformation, but altering the original element.

Build atomic nuclei to explore their instability and resulting radioactive decay

In this simulation, users can add protons and neutrons to create an atomic nucleus, view its half-life and decay options, and identify patterns in how specific combinations of particles create extremely stable nuclei, from which the nuclear shell model of stability emerged.

View the most expensive materials on Earth, led by those forged in particle accelerators

Californium-252—valued at $27.8M per gram, as of 2025—is far rarer and more valuable than gold, silver, or diamonds due to production and transportation costs. The most expensive substance ever found or created is antimatter, costing approximately $62.5T per gram.

An overview of helium, the nonrenewable resource that's lighter than air

The second element in the periodic table naturally forms deep underground over the course of billions of years through the decay of radioactive elements, but it is used and lost to space at rates faster than it is generated. Because of this and its extensive applications in scientific technologies, scientists continue to seek avenues for its exploration, storage, and recycling.

Turning nuclear waste into cancer medications

This video explores Terrapower, a company transforming nuclear waste into lifesaving cancer treatments. This is accomplished through the production and use of Actinium 225, a rare isotope derived from thorium, which is used in targeted alpha therapy to treat cancer.

What are rare earth elements?

Rare earth metals are 17 elements in the periodic table critical for modern technologies like electronics and defense systems. Although the US once led in their production, it now faces significant challenges in competing with China’s lower costs and control of over 70% of the global output.

Distinguishing between natural and artificial, or induced, radioactivity

Naturally occurring radioactivity comes from radioactive elements underground, cosmic radiation from the sun and other objects in space, and radioactive atoms that make up the molecules we breathe, eat, and drink. Artificial radioactivity is predominantly generated for medical applications and industrial activities.

Learn about ionizing radiation and see the most radioactive places on Earth

The average person is exposed to radiation every day, though most of it is either harmless non-ionizing radiation or ionizing radiation at doses too small to significantly affect an individual. The highest doses of ionizing radiation are received by smokers due to the radioactive polonium and radioactive lead in tobacco products.

Uranium's ability to split easily makes it the most common catalyst for nuclear power

Uranium is commonly found in rocks, water, and soil worldwide, but significant industrial processes are needed to process and enrich it for efficient reactor usage. After being irradiated in reactors, it must be cooled down before disposal.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

How scientists determine elemental composition based on the light emitted by cooling atoms

When electrons within an atom drop to a lower energy level closer to the nucleus, they lose energy and produce light with energy equal to the difference between the two energy levels. Because these levels and the corresponding emitted light are unique to each element, the light serves as a unique signature that can be compared to known lab samples for identification.

RTGs convert heat generated by the decay of radioactive plutonium into electricity

Radioisotope thermoelectric generators use a thermocouple—two plates of different metals joined at two junctions to make a closed circuit. When heating one junction while keeping the other cool, a voltage and an electric current are created.

By organizing elements by atomic weight, Dmitri Mendeleev created the periodic table

The organization included groupings based on similar chemical properties and patterns in atomic weights. This left gaps that were used to predict the properties of elements yet to be discovered—including germanium and gallium—with high accuracy.

Scientists keep track of time via light absorbed by cesium and strontium atoms

These absorptions happen in cycles, where one second is defined as 9,192,631,770 cycles of cesium atom radiation. Strontium atoms can be used to make clocks that do not gain or lose a second in 15 billion years.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Simulate the decay of a radioactive substance to visualize its half-life

By definition, the half-life is the amount of time it takes for half of a radioactive sample to decay. With each half-life that has elapsed, half of the starting sample is left, leaving less to decay each time. This results in the number of undecayed atoms decreasing exponentially, with less stable substances having shorter half-lives and decreasing exponentially more rapidly.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Meet the the scientists of the Manhattan Project

This resource profiles the scientists behind the Manhattan Project—from Nobel laureates like Fermi and Bethe to controversial figures like Teller and Fuchs—showing how their ideas, rivalries, and choices shaped the development of the atomic age.

View a list of the worst nuclear meltdowns before 2013

Nuclear meltdowns occur when a reactor overheats and radioactive materials leach into the surrounding environment. While rare, the reasons for each occurrence—as detailed in this piece—can help establish new safety protocols for future reactors.

The term 'low T' was coined in 2002, recasting testosterone therapy and elevating demand

The marketing shift and accompanying awareness campaigns, both by the company behind the first testosterone product approved by the FDA, changed the landscape for testosterone product demand. Testosterone is often considered low when it's below 300 nanograms per deciliter of blood. (Some users may experience a paywall.)

Why taking potassium iodide to protect against radioactivity is unlikely to be effective

Since the thyroid gland cannot distinguish between radioactive and non-radioactive iodine, taking potassium iodide pills causes the thyroid to absorb the medication, leaving it unable to take up radioactive iodine from the environment. However, while this protects the sensitive gland against the most prominent radioisotope produced in nuclear accidents, it does not protect other body parts or shield against other radioactive substances.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Isodope is the world's first nuclear energy influencer

Isabelle Boemeke, a Brazilian fashion model and social media personality, began promoting the benefits of nuclear electricity in 2015. She now debunks common objections to it through her TikTok persona Isodope—which has more than 34,000 followers.

The Non‑Proliferation Treaty was designed to prevent new states from developing nuclear bombs

The Treaty on the Non‑Proliferation of Nuclear Weapons (created in 1968, effective 1970) binds non-nuclear states to forgo nuclear weapons and commits nuclear powers to share peaceful technology and pursue disarmament—forming the core of the global non-proliferation regime.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

View the ten deadliest tornadoes in US history.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

The 1987 Nintendo video game 'Stadium Events' isn't known for being particularly fun, but its scarcity has made it a highly sought-after item that has sold for up to $35K at auction.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

The identity of the Tank Man in the iconic photo from the 1989 Tiananmen Square protests remains unknown and was possibly killed.