Noble gas

Some gases are very quiet.

They do not like to change. They do not mix with other things. This is because their outer parts are full.

Being full helps them stay the same.

One gas helps big balloons fly.

This gas is called helium. It is very light.

Other gases are used in bright lights.

Some gases help with welding.

Scientists find these gases in the air. They can also find them in the ground.

These gases are very special. They help us in many ways.

Noble gases are a special group of elements. They live in Group 18 on the periodic table.

These gases are very quiet. They do not like to react with other things. This happens because their outer shell is full. An outer shell is the space where electrons live.

Most noble gases have no color or smell. They include helium, neon, argon, krypton, xenon, and radon. There is also a man-made gas called oganesson. Oganesson is very unstable. It only lasts for a tiny fraction of a second.

We use these gases in many ways. Helium is very light. It helps blimps and balloons float in the air.

Argon is used in welding. It acts as a shield to stop unwanted changes. Neon and helium can also keep things very cold. This is because they have low boiling points. A boiling point is the temperature when a liquid turns into a gas.

Scientists get most of these gases from the air. They use a way called fractional distillation. This set of steps separates the gases from each other.

Noble gases are a special group of elements in the periodic table. They belong to Group 18.

Most of these gases are colorless and have no smell. They are also called monatomic gases. This means they exist as single atoms rather than groups. They are famous for being very unreactive. This means they do not like to join with other substances. This quiet nature makes them very useful for many jobs.

These gases stay quiet because of how their electrons are arranged. Every atom has an outer shell of electrons. In noble gases, this outer shell is full.

Because the shell is full, the atoms do not need to react with others to find stability. This is often called the octet rule. It means having eight electrons in the outer shell is a very stable state. This rule explains why these gases do not participate in most chemical reactions. Only a few hundred noble gas compounds are known to exist.

Humans discovered these gases over many years. In 1868, Pierre Janssen and Joseph Norman Lockyer found helium in the Sun. They named it after the Greek word for the Sun. Later, Lord Rayleigh and William Ramsay worked together in London. They found that nitrogen from the air was different than expected. This led them to discover argon.

Ramsay also found krypton, neon, and xenon in 1898. He named them using Greek words for "hidden," "new," and "stranger." These discoveries helped scientists understand how atoms are built.

There are seven members in this group. The first six are helium, neon, argon, krypton, xenon, and radon. Helium is very light and helps blimps float.

Argon makes up about 0.94% of our air. Radon is different because it comes from the decay of elements like radium. The seventh member is oganesson. It is a synthetic element made by scientists. They created it in 2006 by bombarding californium with calcium. Oganesson is very unstable and lasts for only 0.69 milliseconds.

We use noble gases in our everyday lives. Helium and neon are used as refrigerants. This is because they have very low boiling points. A boiling point is the temperature when a liquid turns into a gas. Argon is used as a shielding gas in welding. It protects the metal from unwanted reactions. Xenon is used in special bright lamps.

These gases are mostly taken from the air. Scientists use a process called fractional distillation to separate them. This way of working turns air into liquid to pull the gases apart.

The noble gases are a unique group of chemical elements found in Group 18 of the periodic table.

This group includes helium, neon, argon, krypton, xenon, radon, and the synthetic element oganesson. Historically, these elements were called inert gases because they show very little chemical reactivity. This means they do not easily combine with other substances to form compounds. Under standard conditions, the first six members are colorless, odorless, and monatomic gases. Being monatomic means they exist as single, individual atoms rather than molecules. They are also known for having cryogenic boiling points, which are extremely low temperatures.

The chemical stability of noble gases is explained by their specific electron configuration. Every atom has electrons arranged in shells around a nucleus. For most noble gases, the outermost shell, or valence shell, is completely full.

In 1916, physicist Gilbert N. Lewis formulated the octet rule to describe this. The rule states that having eight electrons in the outer shell is the most stable arrangement. Because their shells are already full, these atoms have little tendency to gain or lose electrons. This lack of need for more electrons makes them highly unreactive. While scientists once thought they could not react at all, a few hundred noble gas compounds have since been discovered.

There are several distinct types of noble gases within this group. The first is helium, which is the lightest element and has a unique boiling point lower than any other known substance. Next are the gases like neon and argon, which are commonly used in industry. Moving down the group, the atoms get larger and heavier, such as krypton and xenon. Radon is a heavier, radioactive element that is not stable. Finally, there is oganesson, which is a synthetic element. Unlike the others, oganesson is predicted to be a solid under standard conditions due to relativistic effects.

The history of these gases is a story of scientific discovery spanning over a century. In 1868, Pierre Janssen and Joseph Norman Lockyer discovered helium by observing the Sun's chromosphere. They named it after the Greek word for the Sun, "helios." Later, in 1895, Lord Rayleigh noticed that nitrogen from the air had a different density than nitrogen from chemical reactions. He and William Ramsay worked together to isolate argon, which they named after the Greek word for "idle." Ramsay later used fractional distillation to find krypton, neon, and xenon in 1898. These discoveries were so significant that Rayleigh and Ramsay shared Nobel Prizes in 1904.

Noble gases are vital to many modern technologies and industries. Argon makes up about 0.94% of the Earth's atmosphere by volume. Because it is unreactive, it is used as a shielding gas in welding and as a filler in incandescent light bulbs. Helium provides buoyancy for blimps and balloons, as seen in large airships.

Because of their low boiling points, helium and neon are also excellent refrigerants. Xenon is used in high-intensity applications, such as xenon short-arc lamps.

Even radon has a role, though it is usually isolated from the decay of radium, thorium, or uranium.

Scientists obtain these gases through different methods depending on the element. Most noble gases, except for radon, are extracted from the air. This is done using a process called fractional distillation, where air is liquefied and then separated. Helium can also be found as a byproduct of mining natural gas. Radon is different because it is a product of radioactive decay. In contrast, oganesson is entirely man-made. It was created in 2006 by scientists at the Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory. They produced it by bombarding californium with calcium.

The study of noble gases has deeply influenced our understanding of atomic physics. Early failed attempts to react argon with fluorine helped scientists build better theories. These efforts eventually led Niels Bohr to propose his model of electron shells in 1913. The weak forces between noble gas atoms, known as London dispersion forces, also helped scientists study intermolecular interactions. In 1924, John Lennard-Jones used argon data to help model these forces. Today, the noble gases continue to be essential for studying everything from quantum mechanics to the structure of the universe.