The average banana produces one positron—the antimatter counterpart to an electron—every 75 minutes as its trace amounts of radioactive potassium decay.

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.

Less common types of radioactive decay include emitting neutrons and antimatter

Through neutron emission, one or more neutrons are ejected from atoms that have far fewer protons. Neutrons can also be released by artificially inducing the fission, or separation, of a large atomic nucleus into smaller ones. During beta-plus decay, a positron—the antimatter version of an electron—is produced when a proton turns into a neutron.

Antimatter particles possess the same mass and spin as their normal particle counterparts, but possess an opposite charge and transform into pure energy upon colliding with normal matter.

Why bananas are in trouble

The average American eats over 25 pounds of bananas every year, but we won't for long if a deadly soil fungus continues to spread. Learn what scientists are doing to save the popular fruit.

Antimatter can be created from dark lightning—high-energy light emitted by deflected electrons after they are accelerated to near the speed of light by thunderstorms.

Antimatter's rarity across the cosmos is one of the biggest problems in modern physics because the high-energy environment of the early universe should have produced equal amounts of matter and antimatter.

In 1997, the Compton Gamma Ray Observatory identified 'positron geysers'—fountains of antimatter particles—emerging from near the center of the Milky Way.

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.

Here's why you've never eaten a banana seed

Hank loves bananas and is worried about their future, so he did some investigating and wrote this four-minute episode of SciShow to share some kind of scary banana truths with us.

At CERN's Antimatter Factory, researchers create and guide antiprotons and antielectrons together to form antihydrogen, and all these antiparticles are analyzed to help scientists study the behavior of antimatter.

Antimatter was discovered by examining debris from collisions between atmospheric gases and cosmic rays—high-energy matter particles from space.

A beam of neutrinos can be created by firing a beam of high-energy protons at a target to produce unstable particles that decay into neutrinos.

After photons—particles of light—neutrinos are the most abundant particles in the universe.

With less than 50 milligrams present in the top kilometer of Earth's crust at any given time, astatine is the rarest naturally occurring element on the planet.

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.

Some particles that mediate fundamental forces in nature are their own antiparticles, such as photons—particles of light and mediators of the electromagnetic force.

View a step-by-step breakdown of how helium is forged in stars alongside antimatter

During the proton-proton chain, four hydrogen nuclei—protons—are fused together to create an alpha particle—a helium nucleus—and produce the energy that supports a star's own weight. Through radioactive decay, two of these protons become neutrons, with each releasing an antielectron, or positron, and an electron neutrino.

Depictions of antimatter in science fiction include misleading portrayals of it coming from parallel universes, being mined from asteroids, and serving as a workable laser beam.

An explanation of isotopes, which can help scientists trace food, water, and farming choices

Atoms of the same element have the same number of protons, but experiments showed that atoms of the same element can move through electromagnetic fields as if they had different masses. These differences in mass come from variations in the number of neutrons, which contribute to the stability of atoms by providing a buffer to the repulsion between protons.

Antimatter was predicted to exist four years before it was observed, though the mathematics responsible for the prediction described it as matter with negative energy.

PET scans create images of the body by detecting light emitted from the annihilation of matter and antimatter, with the latter produced by custom chemicals containing radioactive atoms.

View summaries of the most common types of radioactive decay and their associated particles

The alpha particle has the strongest ability to ionize other atoms it strikes, but it also does not travel very far before colliding with something and being absorbed. Gamma particles—high-energy photons—do not interact with matter as easily and therefore possess the greatest penetrating power, though this also makes their ionizing potential the smallest.

If they could be built, antimatter drives, which run on energy released from the collision of matter and antimatter particles, would be the most efficient engines in existence.

Some cosmic rays possess energies as high as 100,000,000 teraelectron volts—more than 10 million times the energy of particles accelerated in the Large Hadron Collider.

View the most expensive materials on Earth, led by antimatter and other elements forged in particle accelerators.

The one-electron theory describes the universe as having only one electron

The thought experiment explains why every electron has the same charge and mass as every other electron, and describes every positron—the antimatter version of the electron—as that same electron traveling backwards in time. Among other foundational challenges, the model suggests that the universe contains equal numbers of electrons and positrons, yet normal matter is much more common than antimatter.

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.

Misleading measurements and fear-based reporting often exaggerate radiation risks

Daily exposure to radioactivity is common but occurs in low doses outside of locations near nuclear accidents like Chernobyl and Fukushima. Researchers have detected radiation in tuna, bananas, and the human body due to increasing instrumental sensitivity, not rising concentrations.

In 2026, researchers successfully transported antimatter in a truck using a portable trap that employed electromagnetic fields to hold 92 antiprotons.

Fusion reactions and radioactive decay produce elements inside stars

Hydrogen, present since the early universe, serves as fuel for the proton-proton chain, producing helium, which is then incorporated into the CNO cycle to produce carbon, nitrogen, and oxygen. Additional fusions of helium with these elements and subsequent decays via the alpha ladder produce elements up to iron and bismuth.

View a ranking of the masses of fundamental particles, from the massless photon to the top quark, and a timeline of their discoveries.

Within ALICE—A Large Ion Collider Experiment—at the Large Hadron Collider, scientists have created quark-gluon plasma—an exotic form of matter present in the moments after the Big Bang.

Particles produced in cosmic ray showers that would normally decay long before they reach Earth's surface are observed in ground-based detectors because they experience time more slowly when moving near the speed of light—a phenomenon predicted by special relativity.

While both are nuclear weapons, atomic bombs release nuclear energy by splitting large atomic nuclei, whereas hydrogen bombs derive most of their energy from fusing heavy hydrogen isotopes.

Before 1932, when particle accelerators were first used for nuclear research, scientists relied on naturally radioactive substances to advance their understanding of the atomic nucleus.

Although they rely on radioactive elements to operate, everyday technologies such as electronic exit signs, some wristwatches, and smoke detectors are not dangerous, unless they are damaged and their radioactive material is inhaled or swallowed.

Learn about solar neutrinos—about 70 billion of which pass through your thumbnail every second

About 100 quadrillion sextillion (10³⁸) of these elusive particles are created in the core every second, making up about 1% of the sun's total energy output. Because they seldom interact with normal matter, highly specialized equipment is needed to detect them, allowing scientists to probe what is happening in the solar core.

An explanation of the weak nuclear force, which can induce some forms of radioactive decay

While the strong nuclear force holds the protons and neutrons together in an atomic nucleus, despite the electromagnetic force pushing protons apart, the weak nuclear force can change the identity, or flavor, of the quarks that make up these particles. In doing so, protons can be converted into neutrons, and vice versa, altering the stability of atomic nuclei.

If particle accelerators did create black holes by packing tremendous energy into a small volume, then trillions would be created in Earth's atmosphere daily by cosmic rays.

The hypothetical matter that neutron stars' cores may contain, including strange quarks

Models of the extreme pressures and energies in neutron stars suggest conditions resembling those believed to have existed within a fraction of a second after the Big Bang. In these environments, the quarks that make up protons and neutrons in trios may instead form pairs that combine to form one quantum object. (Some readers may experience a paywall.)

The Higgs boson is a quanta, or discrete piece, of the Higgs field, which gives elementary particles, such as quarks and electrons, mass as they travel through it.

Helium formation, from radioactive decay inside Earth to nuclear fusion within stellar cores

Over the course of billions of years, uranium and thorium undergo alpha decay, producing helium nuclei—two protons and two neutrons—which become helium atoms after gaining two electrons. This helium becomes trapped in underground reservoirs along with other gases and can be recovered during natural gas extraction.

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.

Delays in the decay of unstable particles provide evidence for time dilation

Physicists used the muon half-life measured in labs to predict how many should reach detectors on Earth's surface after their production in collisions between atmospheric molecules and cosmic rays. Higher detection rates were consistent with a longer half-life due to slower movement through time.

More than 90% of the atoms in the human body were forged by stars, with almost three-quarters originating from the explosion of massive stars.

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.

Once called 'aces,' quarks are fundamental pieces of matter that combine to create over 100 known composite particles, including the proton and neutron.

Simulate the impact of an antimatter bomb, which releases energy from the annihilation of matter with antimatter, around the world.

Watch a visualization of a fission chain reaction

When a neutron collides with an atom, it is absorbed into the nucleus. If the resulting nucleus is unstable, it can undergo a series of decays that turn it into a less massive nucleus while releasing energy and other particles.

Nuclear batteries generate electrical currents using radioactive materials

Rather than using electrochemical reactions to produce the electrons that flow through a circuit, isotopes like nickel-63 undergo beta decay—emitting electrons—which a semiconducting material can absorb to establish a charge imbalance that generates current. Such batteries could provide low-power energy for decades.