Helium (He) is considered as an inert gas of group 18 (VIIIA), and therefore it is a chemical element of the noble gases of the periodic table. In addition, it is the second lightest chemical element on the periodic table, just below hydrogen.
| Symbol | He |
| Atomic number | 2 |
| Atomic mass | 4.003 |
| Discovered by | Sir William Ramsay en Londres, Per Teodor Cleve y Nils Abraham Langlet |
Helium is naturally a colorless, odorless and tasteless gas that can transform to a liquid at a temperature of -268°C. Furthermore, the freezing and boiling points of this element are the lowest known compared to other elements and chemicals.
Likewise, helium is characterized by being the only chemical element that cannot be solidified by cooling at normal atmospheric pressure, for which a pressure of 25 atmospheres and a temperature of -272°C are necessary to be converted to a solid state.
Importance
Helium enters the inert gas group because its outermost electron orbital is filled with two electrons. For this reason, this element or inert gas is widely used in lasers, compressed air tanks, and as a coolant in nuclear reactors..
A great characteristic and importance of helium is that it is the second most abundant chemical element in the universe, just below hydrogen, likewise, it is the second simplest element in the periodic table.
The most important properties and characteristics of helium are shown below.
Properties and characteristics of helium
Physical properties
| Physical properties of helium | Description |
|---|---|
| Melting point | 0.95K (or -272.2eitherC) |
| Boiling point | 4,222K (or -268,928eitherC) |
| Density | 0.1786g/L in STP;0.145g.cm-3at its melting point |
| Critical pressure and temperature | 5.195K;0.227MPa |
| triple point | 2.177K;5.043kPa |
| Appearance (in STP) | colorless gas |
Ice is a gas that belongs to the group of elements known as noble gases, it has no color or odor and has the lowest boiling point of the existing chemical elements.
This gas can be brought to a liquid state, by means of great pressures, but it cannot be frozen.
Chemical properties
| Helium Chemical Properties | Description |
|---|---|
| Electronic configuration | 1stwo |
| first ionization energy | 2372.3 kilojoules per mole |
| second ionization energy | 5250.5 kilojoules per mole |
| Van der Waals radius | 140 picometers |
| enthalpy of fusion | 0.0138 kilojoules/mole |
Helium is a monatomic gas like all those that belong to its group.
Helium is inert, that is does not have chemical reactions under normal conditions, but does when electrical discharges are applied to it or it is bombarded with electrons, forming compounds of an unstable nature that are known as excimers, with tungsten, iodine, fluorine and phosphorus.
Where it comes from and how it is extracted
Helium is very scarce on the planet, the main helium reserves are in the natural gas fields of the United States, in addition a discovery of a large reserve was recently made in Tanzania.
Its production on a large scale is through fractional distillation from natural gas, since this compound contains up to 7% helium.
This method is facilitated because helium has a low boiling point, so low temperatures and high pressures are used to be liquefied.
Where on the planet does it abound?
Although it is very scarce on the planet, helium is the second most abundant element in the universe. This gas constitutes the 24% of the mass of all the elements that are present in the galaxy.
Its abundance is so great that by mass it has a proportion 12 times greater than the total of all the heavier elements together.
In the Earth its concentration is very low and despite the fact that its production is continuous, helium escapes into space due to different situations, among them it is because it is very light.
Helium is present in small amounts in mineral springs, in volcanic gas and meteoric iron. Also in minerals that contain uranium such as uraninite and thorium.
On the other hand, in the heterosphere, helium along with other light gases are very abundant.
Functions in the human body.
Helium does not have any important or specific function in the body, it can only alter the voice to be inhaled directly.
This unique feature is due to the fact that helium molecules are lighter, allowing sound to travel faster and alter the resonance in the vocal cords.
On the other hand the Helium consumption should be limited, as this gas can cause serious health risks It can even cause death.
Helium causes the reduction of air, being lethal if there is a leak of this gas in a closed place.
Benefits in technology
Helium is widely used in high-tech devices in the area of medicine, since this gas is an important part of the equipment that performs magnetic resonance imaging.
Helium is used to cool the superconducting magnets in the scanners used to do these medical studies.
This gas is also used for the production of rocket fuel, as it contributes to the condensation of hydrogen and oxygen used in propulsion systems.
Benefits in society
Helium, although it is not a very common gas, has a positive impact on human health, since participates in medical diagnosis through magnetic resonance equipment.
Even given the importance of helium for this purpose and before its scarcity on the planet, the possibility of limiting the use of this gas for other purposes is being studied.
Gas for breathing
Helium mixed with other gases can be used as a breathable component for space and underwater activities.
The use of this gas is due to the fact that can reduce the narcotic effect of “depth sickness”, which can cause the death of the diver if it makes a rapid ascent from the sea depths.
The mix is usually 80% helium and the rest is oxygen.
Method of transportation
A very famous use of this gas is to inflate airship balloons that are used for recreational and transportation activities. Helium replaced hydrogen, since it is not flammable.
Nuclear technology
Due to having certain cryogenic characteristics, helium is used as a cooling agent in nuclear reactors.