Helium is a noble gas used to inflate balloons.
Gas is a term coined by the Flemish physicist and chemist Jan Baptista van Helmont , born in 1577 and died in 1644 . This scientist started from the Latin word chaos , which can be translated as "chaos" , to arrive at the idea of gas.
A gas is a fluid characterized by low density and its tendency to expand. It can be said that it is a state of aggregation of matter that is reached when the molecules maintain a very weak interaction with each other. The matter, in this way, adopts the volume and shape of the container in which it is located.
Depending on their characteristics, gases are classified differently. Noble gases are chemical elements present in the atmosphere that have the particularity of having a very low reactivity .
Properties of noble gases
Under normal conditions, noble gases are colorless and odorless. Its location on the periodic table of elements is in group 18 .
In total, specialists recognize the existence of seven noble gases: oganeson , radon , xenon , krypton , argon , neon and helium . Since, taking into account the valence, the electron shell appears complete, these gases do not tend to get involved in chemical reactions.
Another feature of noble gases is the closeness between the melting point and the boiling point, separated by less than 10 degrees Celsius . This means that these gases remain in a liquid state only in a limited range of temperatures .
Noble gases are used as components of the breathing gases used in diving.
Your discovery
In 1784 , the French-British Henry Cavendish ( 1731 – 1810 ) noticed the presence in the air of a substance with less reactivity than nitrogen. However, the Englishman Norman Lockyer ( 1836 – 1920 ) and the Frenchman Pierre Janssen ( 1824 – 1907 ) are pointed out as pioneers in the recognition of noble gases. These scientists, while analyzing the Sun 's atmosphere in 1868 , discovered the existence of a low-reactivity gas which they named helium .
Two decades later, Hugo Erdmann ( 1862 – 1910 ) was the one who named a gas with very reduced reactivity as Edelgas (in our language, noble gas). The name arose by analogy to gold , a metal that is linked to nobility and wealth and that shows little reactivity.
Already in 1902 , the Russian Dmitri Mendeleev ( 1834 – 1907 ) incorporated the noble gases into his classification structure of the elements, which would later lead to the formation of the so-called periodic table .
It is interesting to note, on the other hand, that long ago noble gases were also known as rare gases or inert gases . These nicknames, however, fell into disuse.
Use of noble gases
Noble gases have multiple uses. Helium and neon , for example , are often combined with oxygen to create the mixture mentioned as a breathing gas used in scuba diving .
In the field of lighting , krypton , argon and xenon are used in different types of light bulbs , lanterns and lamps .
To support balloons and airships , meanwhile, helium can be used. This noble gas, like neon , is also used in cryogenics .