Helium

Helium is a very light gas.

It is the second lightest thing in space. It is found in the Sun.

Stars make a lot of it.

People first saw it in sunlight. They saw a bright yellow line. This happened during a solar eclipse.

Later, people found it on Earth. They found it in special rocks. It was also found in natural gas.

This gas can fill big balloons. This helps them float high.

It can even change your voice!

Helium is very useful. It helps cool big machines. It is used in many tools. It is a special part of our world.

Helium is a very light gas. It is the second lightest element in the universe.

It is also the second most common element in space. Most helium was made during the Big Bang. Stars also make it. They do this through nuclear fusion. This is a way where small parts join to make bigger parts.

People first found helium in the Sun. In 1868, astronomers saw a bright yellow line in sunlight. This happened during a solar eclipse. Norman Lockyer named it helium. He used the Greek word for the Sun.

Later, scientists found it on Earth. Sir William Ramsay found it in a mineral called cleveite.

Most helium on Earth comes from radioactive decay. This is when heavy elements break apart. This gas is often found with natural gas.

Helium has many uses. It can fill balloons to make them float. It is also used to cool very strong magnets. These magnets are used in MRI scanners.

Helium is a rare resource on Earth. Once it escapes into the air, it floats into space.

Helium is a very special gas found in our universe. It is a colorless and odorless gas that does not harm living things. Scientists call it an inert gas because it does not react easily with other things. It is the second-lightest element in the whole observable universe. After hydrogen, helium is the most common element found in space. It makes up about 24% of the total mass of elements. This is much more than all the heavier elements combined.

Most helium was made during the Big Bang a long time ago. Large amounts of new helium are also made inside stars. This happens through a process called nuclear fusion. In this process, stars join small parts together to make helium-4. This specific type of helium is the most common in space.

On Earth, helium is much harder to find. It is created when heavy elements like uranium break apart. This is called radioactive decay. This gas often gets trapped in natural gas fields deep underground.

Humans first discovered helium by looking at the Sun. In 1868, astronomers watched a total solar eclipse. During the eclipse, Jules Janssen saw a bright yellow line in the light. This line was a special signature in the solar spectrum. Later, Norman Lockyer saw the same yellow line from Britain. He believed this line came from a new element. He named it helium after the Greek word for the Sun.

Scientists later found helium here on Earth. In 1895, Sir William Ramsay isolated it from a mineral called cleveite. He used acid to separate the gas from the ore. At the same time, chemists in Sweden also found it. In 1908, Heike Kamerlingh Onnes did something amazing. He cooled the gas until it became a liquid. He could not make it a solid at normal pressure. It took more work and extra pressure to freeze it in 1926.

We use helium for many important jobs today. It is a great lifting gas for balloons and airships. Because it is so light, it makes them float. A huge part of helium is used for cooling. It cools superconducting magnets in MRI scanners at hospitals.

It is also used in welding and making silicon wafers. Helium is a non-renewable resource on our planet. Once it escapes into the air, it floats away into space. We must use it carefully because our supply is shrinking.

Helium is a unique chemical element with the symbol He and atomic number 2. It is a colorless, odorless, and non-toxic gas that is considered chemically inert. This means it does not easily react with other substances. In the periodic table, helium is the first member of the noble gas group. It is the second-lightest element in the observable universe, following only hydrogen.

Because it is so light, helium is also the second-most abundant element in space. It accounts for approximately 24% of the total elemental mass in the universe. This mass is more than 12 times greater than the mass of all heavier elements combined. This high abundance is seen in both the Sun and the planet Jupiter.

The abundance of helium is driven by its high nuclear binding energy. This energy is specifically related to the helium-4 isotope. This high energy explains why helium-4 is a common product of both nuclear fusion and radioactive decay. Most helium in the universe is helium-4, which was largely formed during the Big Bang. However, stars also create large amounts of new helium. They do this through nuclear fusion, which is the process of joining hydrogen atoms together.

On Earth, helium is much rarer, making up only about 5.2 parts per million by volume in our atmosphere. Most of our terrestrial helium comes from the radioactive decay of heavy elements like thorium and uranium. As these elements decay, they emit alpha particles, which are actually helium-4 nuclei. This gas often becomes trapped in natural gas reserves deep underground.

The history of helium began with observations of the Sun. During a total solar eclipse on August 18, 1868, astronomers noticed something unusual. French astronomer Jules Janssen detected a bright yellow spectral line in the Sun's chromosphere. A spectral line is a specific signature of light that helps identify elements. At first, many thought this line was just sodium. However, English astronomer Norman Lockyer observed the same yellow line from Britain. He named this signature the D3 line because it was near the known D1 and D2 lines of sodium.

Lockyer was the first to propose that this line belonged to a new element. He named the element helium after "helios," the Greek word for the Sun.

It took several more decades to find helium on our own planet. In 1881, Italian physicist Luigi Palmieri detected helium in material from an eruption of Mount Vesuvius. The formal isolation of the element occurred in 1895. Scottish chemist Sir William Ramsay isolated helium by treating a mineral called cleveite with mineral acids.

Cleveite is a variety of uraninite containing rare-earth elements. At the same time, chemists Per Teodor Cleve and Nils Abraham Langlet independently isolated the gas in Sweden. They collected enough to determine its atomic weight. This discovery proved that the element Lockyer saw in the Sun actually existed on Earth.

Scientists have also studied the extreme physical properties of helium. In 1908, Dutch physicist Heike Kamerlingh Onnes succeeded in liquefying helium. He did this by cooling the gas to temperatures below 4 Kelvin.

Interestingly, he found that helium would not solidify at standard atmospheric pressure. It was not until 1926 that Willem Hendrik Keesom successfully solidified a small amount of helium. He achieved this by applying additional external pressure. Today, researchers study the different fluid phases of helium-4, known as helium I and helium II. These phases are important for understanding quantum mechanics and the property of superfluidity. Superfluidity allows the liquid to behave in strange ways, such as creeping along surfaces.

Helium has many vital industrial and scientific applications. One of its largest uses is in cryogenics, which is the study of very low temperatures. About one-quarter of all helium production is used for this purpose. It is specifically used to cool superconducting magnets in MRI scanners.

Other industrial uses include providing a protective atmosphere for arc welding. It is also used in processes to grow crystals for silicon wafers. Because helium is so light and does not burn, it is a common lifting gas for balloons and airships.

Despite its many uses, helium is a non-renewable resource on Earth. Because it is so light, once it is released into the atmosphere, it quickly escapes into space. Most of our supply comes from natural gas fields, such as those found in the United States. In these fields, helium can reach concentrations as high as 7% by volume. We extract it using a low-temperature process called fractional distillation. Because our supply is rapidly diminishing, managing this precious element is a major concern for science and industry.