Hydrogen

Hydrogen is the lightest thing in space.

It is everywhere in the universe. It also makes up most of our Sun.

On Earth, this gas is in water. It can be made from water too.

People use it to make food for plants.

This gas can burn very fast. It makes a tiny blue light. It is hard to see in the day. It is a very special part of our world.

Hydrogen is the lightest element in the universe.

It makes up about 75% of all normal matter. Most stars, including our Sun, are made of hydrogen.

On Earth, we find hydrogen in many ways. It is a gas that has no color or smell. It is also part of water. Hydrogen can burn very fast. When it burns, it makes water.

This fire makes a faint blue light. It can be hard to see in daylight.

There are different types of hydrogen called isotopes.

The most common type is called protium. It has one proton and one electron. Another type is called deuterium. It has one proton and one neutron. A third type is called tritium. Tritium is radioactive. People use it in glowing watch parts.

Scientists also use hydrogen to make fuel. This can help make electricity.

Hydrogen is the lightest and most common element in the universe.

It makes up about 75% of all normal matter. Most stars, including our Sun, are made of hydrogen in a plasma state. On Earth, we usually find it as a colorless and odorless gas. This gas is called dihydrogen or molecular hydrogen. It is also found in water and organic compounds.

Hydrogen is highly combustible, which means it burns very easily. When it burns with oxygen, it creates liquid water.

There are three natural types of hydrogen called isotopes.

The most common is protium, which has one proton and one electron. It has no neutrons in its nucleus. The second type is deuterium, which has one proton and one neutron. People use "heavy water" made with deuterium in nuclear reactors. The third type is tritium, which has one proton and two neutrons. Tritium is radioactive and can be used in glowing watch dials.

These different versions help scientists study how atoms work.

Scientists have studied hydrogen for a long time to understand light.

Learning about the colors of light from hydrogen helped create quantum mechanics. This is a big part of how we understand tiny particles. In the 1700s, Henry Cavendish identified hydrogen as its own substance. He discovered it produces water when it burns. This discovery is why we call it "hydrogen." The name comes from Greek words meaning "water-former."

We use hydrogen in many ways in our modern world.

Most hydrogen is made by changing fossil fuels through steam reforming. We can also use electrolysis to pull it from water. This uses electricity to split water into its parts.

Industry uses hydrogen to make ammonia for fertilizer. It is also used in processing fossil fuels. New technology uses fuel cells to turn hydrogen into electricity.

Hydrogen behaves in many different ways depending on its environment.

At very high pressures, it can become a metal that carries electricity. This might happen deep inside giant planets like Jupiter. In space, hydrogen atoms formed 370,000 years after the Big Bang. As the universe grew, the plasma cooled down enough for atoms to form. Hydrogen is also part of the acid-base reactions in water. This helps control the pH, or the acidity, of a liquid.

Hydrogen is the most abundant chemical element in the universe.

It makes up about 75% of all normal matter. Hydrogen is the lightest element known to science. In the massive stars of space, it exists as a plasma. On Earth, we typically encounter it as a gas called dihydrogen. This gas is colorless and odorless. It is also non-toxic but remains highly combustible.

This means it burns very easily when it meets oxygen.

To understand hydrogen, we must look at its atomic structure. The most common isotope is protium, which has an atomic number of 1. A protium atom consists of one proton and one electron. It contains no neutrons in its nucleus. Other isotopes exist with different arrangements of particles.

Deuterium is a stable isotope containing one proton and one neutron. Tritium is a radioactive isotope with one proton and two neutrons. Tritium decays into helium-3 through a process called beta decay. This decay happens with a half-life of 12.32 years.

Hydrogen behaves differently depending on its chemical state. In ionic compounds, it can take two different forms. It can be a positively-charged cation called a hydron. It can also be a negatively-charged anion called a hydride.

Hydrons are very important in acid-base reactions. These reactions involve the exchange of protons between molecules. Hydrides are much rarer because they tend to react with solvents. Hydrogen also forms covalent bonds with most nonmetals. This allows it to create essential molecules like water and organic compounds.

Scientists have used hydrogen to unlock the secrets of the universe. In the 18th century, Henry Cavendish identified hydrogen as a distinct substance. He observed that it produces water when it is burned. This discovery led to its name, which comes from Greek words meaning "water-former."

Later, studying the light emitted by hydrogen was vital. Understanding the colors of light absorbed and emitted by hydrogen helped develop quantum mechanics. This field explains how tiny particles behave at the smallest scales.

Scientists use the hydrogen spectral series to study these energy transitions.

Hydrogen is produced on a massive scale for industrial use. Most hydrogen today comes from transforming fossil fuels. A common method is steam reforming of natural gas. Another way to produce it is through electrolysis. This process uses electricity to split water or saline into its components. While electrolysis is effective, it is currently more expensive than reforming. Industry uses this hydrogen to create ammonia for fertilizer. It is also used in the processing of various fossil fuels. Newer technologies use fuel cells to turn hydrogen into electricity.

Physical properties of hydrogen change under extreme conditions. At standard pressure, hydrogen is a gas. However, it can be liquefied if cooled to -252.87 degrees Celsius.

James Dewar first liquefied hydrogen in 1898 using a vacuum flask. If you apply extreme pressure, hydrogen can become metallic. Metallic hydrogen is an electrical conductor. Scientists believe this phase exists deep inside giant planets like Jupiter. In the early universe, neutral hydrogen atoms formed 370,000 years after the Big Bang. This happened as the expanding universe cooled enough for electrons to bind to protons.

Hydrogen plays a role in many different scientific systems. It is a key part of the intergalactic medium in space. It is also central to the study of pH in aqueous solutions. The presence of hydrons affects how acidic or basic a liquid is. In nuclear science, deuterium is used as a coolant in reactors. It is also a potential fuel for future nuclear fusion. Tritium is used in specialized self-powered lighting devices. It can even be used in luminous paint for watch dials. This makes hydrogen one of the most versatile elements in existence.