It is the first element in the periodic table and its symbol is H. It is one of the main components of water and of all organic matter.
Hydrogen is found in abundance in stars, since it is widely related to their creation, also in the gaseous planets like Jupiter and Venu s. Hydrogen is said to make up more than 70% of the visible matter in the universe.
Diatomic hydrogen gas, H2, was the first to be produced artificially, and the scientist Theophrastus von Hohenheim was responsible for it.
As early as 1671, other contributions were made around H2. Robert Boyle described how hydrogen is created from the reaction between iron filings and dilute acids.
It was Antoine Lavoisier who in 1783 gave the name to this element taken from the Greek hydro (water) and genes (to generate).
In the 20th century, H2 was used to fill airships and hot air balloons, but due to the large number of accidents that occurred, its use was stopped and helium (which is not flammable) was used.
Hydrogen was first liquefied by James Dewar in 1898.
Hydrogen is composed of diatomic gas molecules, H2, this, under normal conditions of temperature and pressure.
Its atomic structure is somewhat simple compared to that of other elements, it has a single proton and a single electron for protium , which is its most abundant isotope (99.98%). The other isotopes are: deuterium (0.02%) and tritium , which can be produced artificially.
H2 has atomic number 1 and an atomic weight of 1.00797 amu (molecular mass). Hydrogen gas has a density of 0.0899 kg / m3, a melting point of 14.025 K (−259 ° C), a boiling point of 20.268 K (−253 ° C), and a flash point of 255 K (−18 ° C).
The rest of the characteristics are:
- Group : 1
- Period : 1
- Appearance : colorless
- Block : s
- Density : 0.0899 kg / m3
- Average radius : 25 pm
- Atomic Radius : 53
- Covalent Radius : 37 pm
- Van der Waals radius : 120 pm
- Electronic configuration : 1s1
- Electrons per shell : 1
- Oxidation states : 1, -1
- Oxide : amphoteric
- Crystal structure : hexagonal
- State : gaseous
- Heat of fusion : 0.05868 kJ / mol
- Vapor pressure : 209 Pa at 23 K
- Critical temperature : 23.97 K
- Critical pressure : 1,293106 Pa
- Molar volume : 22.42 × 10-3m3 / mol
- Electronegativity : 2.2
- Specific heat : 1.4304104J / (Kkg)
- Electrical conductivity : – S / m
- Thermal conductivity : 0.1815 W / (K m)
The dihydrogen (hydrogen gas) is highly flammable, burns when a 4% or more of H2 in air. The enthalpy, that is, its thermodynamic magnitude, is −285.8 kJ / mol.
When this element mixes with oxygen, in a certain amount, an explosion can occur. Combustion occurs rapidly at a temperature of 560 ° C.
The curious thing about this eventuality is that a flame detector will be needed to know if there is an ignition formed by concentrations of this element and oxygen, since it is almost invisible to the eye.
There are many uses that hydrogen can be given in any of its states . Next, we will mention some of them:
- It is used to process fossil fuels.
- In the manufacture of ammonia for household cleaning products.
- It is a hydrogenating agent to produce methanol.
- Converts unhealthy unsaturated oils and fats into saturated oils and fats.
- When the temperature of its three states: solid, liquid and gaseous, are in equilibrium (triple point), it can be used to calibrate some thermometers.
- The artificially created isotope, tritium, can be used to create hydrogen bombs and also functions as a source of radiation in luminous paints.
- It is used in the detection of leaks in manufacturing plants of many products, such as food packaging.
- H2 is widely used as a refrigerant in electric generators.
- In its gaseous state , it is used as a shielding gas in atomic hydrogen welding.
- To produce hydrochloric acid, which is widely used in chemical industries.
- The gas is used to reduce many metallic minerals.
- As a component of water, it can be used to produce this liquid.
- As a propeller for hot air balloons and zeppelins
Human beings are exposed to hydrogen on many occasions as it is one of the most found elements in nature. However, under certain circumstances it may cause us some harm, such as burns from flames or explosion.
Furthermore, it is a highly absorbable substance by inhalation. People may have a headache, ringing in the ears, dizziness, drowsiness, unconsciousness, nausea, vomiting, and weakness.
Examples of hydrogen
Products that can be created with hydrogen:
- Space fuels
- Fuel for cars
- Controlled fusion to generate electricity
Examples of foods with hydrogen :
Examples of covalent compounds containing H2:
- Ammonia (NH 3 )
- Hydrazine (N 2 H 4 )
- Water (H 2 O)
- Hydrogen peroxide (H 2 O 2 )
- Hydrogen sulfide (H 2 S)