Different types of ice link water molecules together in unique shapes

There may be 74,963 kinds of ice, resulting from water molecules rearranging themselves

The theoretical limit greatly expands the known types of ice, with type Iₕ being the most common on Earth and forming hexagonal crystals. The extreme environments of planets like Uranus and Neptune can create a variety of ice with unique structures and properties, as these conditions can reshape these crystals into new geometries.

If the temperature of water continuously decreases but it is not given room to expand, it will eventually contract and form exotic forms of ice that sink in liquid water.

Snowflakes form when water vapor turns directly into ice

Every water molecule has a slightly bent shape due to electron repulsion and regularly forms bonds with hydrogen molecules. When they freeze, they form a six-sided (or hexagonal) lattice, resulting in the six-sided symmetry of snowflakes. As the snowflake falls, more water molecules freeze onto its six sides, forming the unique, beautiful geometric designs.

A chemical overview of water, whose uncommon properties help sustain life on Earth

The uneven distribution of charge in water molecules allows them to bond to each other and to surfaces, enabling them to move against gravity, including up plants through roots and stems. These bonds also keep water in a liquid state over a wider temperature range and make it less dense as it freezes. This causes ice to float and form an insulating layer for underwater ecosystems, from which all life originated.

Simulations suggest ice's slipperiness comes from rearranging molecules

Past models have proposed that slipperiness arises from a thin layer of liquid water formed at the ice's surface by frictional melting. However, new research suggests that electromagnetic forces between interacting surfaces push water molecules out of an ordered, crystalline structure and into a shapeless, soft, slippery layer. This process occurs solely through contact, independent of pressure or friction.

Is ice slippery because of amorphization—a chaos of molecules caused by sliding?

Traditional explanations cite three factors that make ice slippery: pressure, friction and so-called premelting. A fourth has been proposed in recent years: amorphization, that sliding along some surfaces creates molecular disorder, causing liquid-like behavior.

Fish in polar waters contain proteins in their blood that act as antifreeze, and some manufacturers have used lab-grown versions of these proteins to help keep ice cream smooth.

Ice cream’s unfrozen consistency is thanks to sugar

Making ice cream is a complex, multistep scientific process. But the treat’s scoopable, chewable consistency is due to the product’s dissolved sugar.

As crystals form, their properties and the shapes they take on, including cubic, tetragonal, and hexagonal patterns, reflect the arrangement of their constituent atoms.

Cooling lava naturally creates hexagonal cracks to evenly relieve stress

When lava cools and turns into rock, it contracts and builds up tension, particularly when held in place by the surrounding landscape. Just as drying mud cracks, initial cracks in the rock are random, but quickly organize into a hexagonal pattern, which scientists consider the most space-efficient shape.

High freezing speed restricts the development of gritty crystal chunks in ice cream

For this reason, ice cream does not maintain its smoothness when refrozen in a traditional freezer over several hours. The smooth texture is also made possible by balancing fat, sugar, and emulsifiers.

How chemical bonds between atoms form molecules and large geometric structures

In ionic bonding, one atom transfers at least one electron to another atom, forming two atoms of opposite charge. These atoms attract one another and can stack up in a 3D grid called a lattice. Covalent bonding, where electrons are instead shared, can produce enormous molecules, such as the two found in human chromosome 13, which each contain 37 billion atoms.

At 0.01 degrees Celsius (32.02 degrees Fahrenheit) and about 0.6% of Earth's surface pressure, water simultaneously exists as a solid, liquid, and a gas.

Distinguishing club soda, seltzer, and sparkling water

The three forms of drinking water are similar, but their differences lie mostly in the presence and proportion of minerals and carbonation. Read this quick explainer on the major differences.

Under certain conditions, very hot liquids can freeze more quickly than cooler ones—a phenomenon called the Mbemba effect, after the Tanzanian high school student who accidentally observed it.

Why water is the universal solvent, despite not being good at dissolving many substances

Because oxygen attracts electrons much more strongly than hydrogen does in H₂O, the molecule is polar, with a negative charge at the oxygen atom and positive charges at the hydrogen atoms. These charged regions can attract and pull apart charged portions of other polar molecules, such as washable inks, but are unable to dissolve nonpolar materials, such as glass and asphalt.

What is freezing fog?

Freezing fog is a weather condition in which fog containing supercooled water freezes on contact with objects, forming a layer of ice and possibly dangerous driving conditions. Get the breakdown with this explainer.

A breakdown of gelling agents used to modify a liquid's texture

Gelatin, agar, and other substances form a structural network that traps liquid, making it appear solid and enabling chefs to create stable layers in pastries and confectionery products. In different concentrations, they can also be used to thicken liquids into gels or encase them in gelatinous spheres.

A guide to making ice cream with liquid nitrogen by flash-freezing dairy

Only existing in liquid form at extremely low temperatures, nitrogen can rapidly freeze cream, coconut milk, and other liquids into small crystals, producing smooth, creamy ice cream. As a safety precaution, liquid nitrogen should be handled in a well-ventilated area with safety goggles and protective gloves.

Ice found in another star system for the first time

NASA's James Webb Space Telescope has discovered frozen water in a young star system. The ice is similar to that found in Kuiper Belt objects in our solar system, and provides insights into planetary formation processes.

The conditions needed for cloud iridescence, or rainbow clouds

The relatively rare phenomenon occurs when sunlight scatters off tiny water droplets or ice crystals in thin, newly-forming or semi-transparent clouds, such as altocumulus, cirrocumulus, lenticular, and cirrus varieties. This effect is similar to what is seen in soap bubbles and mother-of-pearl shells and produces pastel-like colors.

Ice cream, gelato, sorbet, and Italian ice are all popular cold desserts, though they have many important differences.

Distinguishing polar and nonpolar molecules and why charges get distributed unevenly in molecules

Because each element has a unique number of protons and configuration where electrons exist, they attract electrons that are shared with other elements in chemical bonds to varying degrees. When this attraction—electronegativity—varies between two bonded elements, electrons are more likely to be near the more electronegative element and away from the less electronegative element. This can create regions of opposite charge, or poles, and thus polar molecules.

The composition of comets earned them the nickname 'dirty snowballs'

The icy relics of the solar system are composed of rock, gravel, dust, and frozen molecules, such as carbon dioxide, carbon monoxide, methane, ammonia, and water. Once close to the sun, these compounds sublimate into gases, creating a fuzzy cloud that earned the comets another nickname in history: hairy stars.

Despite being called 'ice giants,' Uranus and Neptune do not contain plentiful frozen water—the term refers to their abundance of elements heavier than hydrogen and helium.

Once cooled to temperatures just above 2 Kelvin, helium atoms exhibit a quantum property that removes internal friction, allowing the fluid to climb up walls.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Why Water Towers Are Built This Way

Hail forms in freezing temperatures thousands of feet above the ground

Even if surface temperatures are well above freezing during the summer, updrafts during thunderstorms can push raindrops high into the atmosphere, where they can freeze and form hail. Giant hailstones the size of softballs require updrafts of close to 100 mph.

Freezer burn is the result of moisture leaving ice cream, something that's easily avoidable.

How geometry and uneven charge distribution make some molecules greenhouse gases

Molecules vibrate and rotate with different frequencies based on their elemental composition and shape, which can produce uneven distributions of electrons, as seen in carbon dioxide and water. The resulting unbalanced electric field can interact with electromagnetic waves of the same frequency, causing the molecule to absorb the radiation.

Explaining the Leidenfrost effect, where water can hover and move against gravity

Water droplets can glide across surfaces whose temperatures are well above water's boiling point. This heat instantly vaporizes the bottom of the droplet, creating a layer of steam that the rest of the droplet rides and bounces upon. This can be seen when sprinkling water on skillets to determine if the surface is hot enough to cook on.

How glaciers melt

Greenland and Antarctica are home to most of the world's glacial ice, including its only two ice sheets, making them areas of particular interest to scientists. Watch this three-minute video to learn why understanding them is not just interesting, but crucial to our near-term adaptability and our long term survival in a changing world.

Cloud formation requires water vapor and condensation nuclei to build from

The nuclei—particles like dust, salt, and smoke—act like jumpstarts that water molecules can start to accumulate onto to form clouds. Condensation nuclei are about 1/100th the size of cloud droplets, which are mostly water.

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.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

What causes hail?

Hail can be a particularly destructive element of certain thunderstorms, occurring even during otherwise warm days. Learn about the dynamics that lead to ice chunks falling from the sky.

Ice ages are periods of glaciation that last tens of millions of years

During these periods, Earth grows cold and is covered in massive continental ice sheets. Scientists have outlined at least five major ice ages, which result from the alignment of complex factors, like the flow of ocean currents and the movement and location of tectonic plates.

Our bodies cool us down by sweating because water requires a significant amount of energy to change state from liquid to gas, making it an ideal medium for carrying thermal energy away from our bodies.

The structure of DNA helices comes in three major varieties

The hereditary molecule can take the form of A-DNA, B-DNA, or Z-DNA based on environmental conditions such as ion concentration and humidity—a characteristic identified by Rosalind Franklin. A-DNA is the shortest and widest of the three, while Z-DNA is the longest and narrowest. B-DNA—the most common variety in living cells—is the intermediate.

Geode formation begins with trapped gas bubbles in igneous or sedimentary rock

Over thousands or millions of years, water seeps into the cavity created by the bubble and deposits minerals, which slowly build and crystallize into quartz, agate, amethyst or other crystals.

Watch a server submerged in a fluid continue to run and stay cool by boiling the liquid away.

Learn why magnets, like statically charged balloons, can deflect water

While the oxygen atom in water molecules strongly attracts hydrogen's electrons—producing an uneven charge distribution that pulls water toward balloons that have been rubbed against surfaces—the presence of a magnetic field alters the path of these electrons, which produce their own tiny magnetic fields. The interaction of these fields repels water away from magnets, making it diamagnetic.

Stacking nucleotide molecules like toy blocks helps build DNA's structure

Each nucleotide is made up of a sugar—deoxyribose—a phosphate group, and one of four bases that contain nitrogen. Like building a two-tone, spiral staircase from the ground up, nucleotides are linked one on top of another so that sugars and phosphates alternate. The twisted strands are held together by hydrogen bonds between base pairs.

Lichtenberg figures capture lightning-like patterns within insulators

When high-energy electrons from particle accelerators are fired into materials like acrylic, they form a charged plane before discharging into scarred patterns within the material. By evenly charging a cylindrical bottle through rotation during the irradiation process, a 3D figure of lightning in a bottle can be created.

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.

Adhesion molecules and intercellular junctions allow cells to connect together

While some organic structures are mostly composed of non-cellular components (e.g., collagen and calcium phosphate minerals in bones), tissues and organs composed of connected cells rely on specialized proteins and connections to create watertight seals that protect cells within the interior from environmental molecules.

Although the moon's dark spots were named "maria"—the Latin word for "seas"—in 1645, water was not confirmed on the sunlit surface of the moon until 2020.

How freeze-drying leaves food with less than 4% of its original water content

In specialized equipment, foods are brought down to temperatures below freezing before a vacuum pump removes the air from the container, lowering the pressure around the food and the boiling temperature of water. Heaters beneath the food slowly raise its temperature above the now-reduced boiling point, causing the water to go from a frozen to a gaseous state.

Synthetic diamonds may be used to cool microchips

The strong carbon bonds in diamonds efficiently carry vibrations, allowing them to conduct heat several times faster than copper, a metal commonly used in heat sinks. AI and high-performance computing have pushed researchers to investigate alternative materials for cooling solutions.