Create anything from the elements in Little Alchemy 2

The history of chemistry up to World War I, from alchemists seeking gold to probing atomic structure

Those involved in the predecessor of the modern scientific discipline engaged in experimentation to develop recipes that would transform ordinary matter into gold and to create medicines, cosmetics, dyes, and alloys. Over the course of centuries, scientists identified unique elements, organized them based on their properties in the periodic table, and eventually developed the technology to discover the internal structure of atoms.

Play Infinite Craft, an AI software-powered game

In this browser-based game, users combine the elements of earth, wind, fire, and water to create an infinite number of new elements. Try your best to make as many natural phenomena as you can as you build up to the multiverse.

Smaller than atoms—what are quarks?

One of humanity’s eternal questions surrounds what we are fundamentally made of. Many ancient philosophies believed in a set of classical elements: from water, air, fire and earth of ancient Greeks; to…

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.

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.

Build atoms to learn about atomic number, mass number, and charge notations

In this simulation, users can add protons, neutrons, and electrons to create atoms, view their stability and atomic configurations, and identify how the amounts of these subatomic particles are detailed around the abbreviation for the resulting element using AZE notation.

Learn how the Earth was made

Four and a half billion years ago the Earth formed from dust in space to become a molten ball of rock orbiting the sun. Travel back in time to investigate how the Earth was made.

Earth is the only planet in our solar system with fire

And while the sun seems like fire, and other planets have volcanoes, the sun and lava aren't the same thing as fire. To produce fire, a planet needs three ingredients: oxygen, fuel, and heat. No other planet has all three.

Early Earth lifeforms likely made energy via mineral reactions, not sunlight

Earth's initial atmosphere was filled with carbon dioxide, methane, and water, with most oxygen locked away in the rocky crust. Over time, bacteria evolved to slowly release that oxygen into the atmosphere by breaking down rock.

Dragon seismometers, Baghdad batteries, and more ancient artifacts

The ancients were behind us in many ways, but some inventions from the time have not been surpassed in the modern era in effectiveness, beauty, or cleverness. This quick list of bizarre ancient inventions includes a battery from Baghdad, a Molotov cocktail-like explosive in Greece, and more.

The key ingredients to life on Earth—and elsewhere

Life can only arise in incredibly specific conditions, an abundance of certain substances like water and phosphorus, lots of time, and the right proximity to a heat-and-light-providing star. These two experts on evolution of life say above all, life requires luck. Here's a list of eight ingredients to life.

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.

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.

The simple grandeur of atomic theory

Is the universe made up of a continuous substance, or a finite amount of tiny, indivisible atoms? The atomic hypothesis, largely vindicated in the 20th century, was forgotten for nearly 2,000 years after first being formulated by the Greek philosopher Democritus. Learn more about the theory and its implications for science and human life with this reflective essay.

Where does your glass come from?

Glass is created from silica sand, soda ash, and limestone. The more transparent you want your glass to be, the higher the purity you need from your silica—a rarity. Colorless, low-iron glass featured in skyscraper windows and Apple's cube-shaped showrooms has increased demand for such pure silica.

The quantum model of the atom resulted from over two millennia of scientific thinking

In 440 BCE, Democritus proposed that everything was made up of tiny particles surrounded by empty space, which varied in size and shape based on the substance's properties. It was not until the 20th century that experimental evidence validated elements of Democritus' model.

Abiogenesis explains how Earth's natural processes could have formed organic matter

The theory details how chemical interactions in hydrothermal vents and shallow ponds billions of years ago could have created lipids, proteins, and RNA. As these interactions involve water, life is thought to have started in oceans.

Explore Earth's atmosphere and what its layers contain in this interactive adventure

In this interactive, users can move from Earth's surface up through its atmosphere, exploring the natural phenomena found in each layer, including atmospheric rivers, auroras, and meteor showers. Artificial structures such as weather balloons and the International Space Station can also be found on the adventure.

Explore the chemical compounds found in fireworks

Besides the various salts and metals used to produce fireworks colors, shells are also filled with gunpowder and oxidizers to help fuel and accelerate reactions. Chlorates help strengthen colors, while dextrin, a starch, helps hold mixtures together.

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.

About 99% of Earth's atmosphere is made of nitrogen and oxygen

At 78% and 21% respectively, the two elements are followed by argon with almost 1%. Trace amounts of other molecules, including greenhouse gases such as methane and carbon dioxide, and particulate matter such as dust and pollen, make up the remainder of the atmosphere's contents.

Besides the periodic table, there are over 1,000 alternative ways to organize the known elements, with many arrangements emphasizing specific trends among them.

Explore an interactive periodic table of each element's history, properties, and uses.

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.

Elements, isotopes, and ions can be identified by the number of protons, neutrons, and electrons within the atoms that make up a substance.

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.

Hypotheses on the origins of Earth's water, from comets and asteroids to magma oceans

Before Earth's atmosphere formed, any liquid water would have boiled off, preventing the accumulation of water early on to create today's oceans. Planetary scientists continue to debate whether this water was delivered later from comet or asteroid collisions or via reactions between iron oxide in Earth's molten surface and hydrogen gas from the planetary nebula.

Diamonds have been made from substances such as peanut butter and carbon dioxide, though they can be created from any carbon-rich material under extreme pressure and temperature.

Learn more about the history of fireworks, which date back to an accidental invention during an alchemist's quest for information about immortality.

How gold, platinum, and many rare earth elements form during neutron star mergers

While massive stars naturally fuse elements as heavy as iron, an analysis of gravitational waves from the collision of two neutron stars revealed that more massive elements are created in this environment via rapid neutron capture—the r-process. This phenomenon sees existing iron nuclei absorb plentiful free neutrons, many of which decay into protons, creating new elements.

The history of metallurgy: an interactive timeline

Humans have long been shaping metals into useful tools and aesthetic accessories. By 8,700 BCE, humans already had mastered four types of casting copper. Within a few thousand years, people were combining metals to make the alloy bronze and had...

A list of five scientific theories that were accepted and later disproved

Humoral theory held that everyone's personality derived from different combinations of four bodily fluids: blood, phlegm, yellow bile, and black bile. The phlogiston theory stated that all combustible materials possessed a fire element—phlogiston—that was released and absorbed by the air during burning. When the air became saturated with phlogiston, the fire would go out.

Earth's first oceans may have been as much as 230 degrees Celsius (446 degrees Fahrenheit), with atmospheric pressure preventing them from boiling.

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

The outermost shell of electrons in an atom dictates how it bonds to other atoms, including those of the same element, and the properties of the materials composed of those atoms.

See how fireworks are made and which metals are responsible for different colors.

The history of blood, as told by a hematologist

Since ancient times, blood has been seen as a semi-magical substance. Alchemists theorized it was a mixture of the four elements. Others proposed it was one of four bodily fluids whose balance dictated health. This 2019 essay by a hematologist reviews blood's reputation across cultures and centuries.

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.

Before discovering cells, life was believed to emerge suddenly from inorganic matter

Popularized by Aristotle in the 4th century BCE, spontaneous generation was used to explain phenomena like mice appearing in seemingly sealed grain storage. The invention of the compound microscope in the late 16th century led to the identification of cells as the basic unit of life, but it was not until 1855 that their origin from preexisting cells was established.

The history of the periodic table and how it hinted at atoms possessing internal structure

In 1869, more than two decades before the discovery of electrons, Russian chemist Dmitrii Mendeleev organized known elements by atomic weight and chemical properties using index cards. His organization revealed previously undiscovered elements and identified patterns in the reactivity of elements, which would later be linked to each element's outermost electron shell. (Some readers may experience a paywall.)

Rocks, crystals, and gemstones are all made of minerals—solids that form from natural processes, such as evaporated water leaving salt behind or lava rapidly cooling into a solid.

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.

Instead of consuming water and carbon dioxide to produce oxygen and sugar, anoxygenic photosynthesis involves alternative reactants and products.

View a breakdown of the elemental composition of the major celestial bodies in the solar system.

The periodic table organizes elements by atomic structure and common properties

Developed by Dmitri Mendeleev in 1869, the arrangement places elements into columns, called groups, if they share the same number of electrons in their outer shell, indicating similar chemical behavior. From left to right across rows, or periods, elements have more protons, as well as corresponding electrons when neutral.

When did people start making and using glass?

This article details the search for the ancient origins of glass, a now-common item through which archaeologists can spot histories of trade and innovation. Bronze Age glass was made from crushed quartz instead of sand, and artisans could color glass with materials such as cobalt. These trace metallic add-ons have given scientists a vital clue into the origins of glass, which is currently debated as either Egypt or the Near East.

Explore an interactive database of critical minerals and their uses

Columbia University's Critical Materials Monitor identifies 56 elements required for the clean energy transition. The tool provides details on the reserves, production, and trade of each element, alongside what materials are needed for each technology (desktop only).

The world's first artificial element, technetium, was discovered 68 years after its existence was predicted in order to fill a gap in the periodic table.

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.

The history of Earth's breathable atmosphere, made possible by photosynthetic bacteria

Between 3.2 billion and 2.8 billion years ago, threadlike microorganisms called cyanobacteria began consuming available water vapor, carbon dioxide, and sunlight to produce oxygen. However, molecules released from Earth's interior by volcanoes consumed this oxygen via chemical reactions, preventing it from accumulating until volcanism had sufficiently decreased about 2.4 billion years ago.