Hydrogen is a highly flammable chemical element which occurs in great abundance throughout the universe. In fact, hydrogen makes up approximately 75% of the universe, by volume, and it appears in a very large number of compounds, especially those which make up various organic materials. Many people are familiar with hydrogen as a potential fuel source, thanks to its promotion as a potential alternative fuel, and all of us consume hydrogen every day, in the water we drink and the foods we eat.
The atomic number of hydrogen is one, and it is identified by the symbol H on the periodic table. Hydrogen is a unique standalone element, not classified with any other elements. Many scientists think of hydrogen as a kind of elemental building block, since its simple structure is the basis of so many things. The colorless, highly flammable gas has a number of industrial uses, especially in the refining of petroleum products.
The history of the discovery of hydrogen is quite lengthy. Like other gases, hydrogen rarely appears in a pure form on Earth, and it took some time for people to understand that hydrogen was an element. Hydrogen gas was described as early as the 1400s, when experimenters combined acids and metals to produce a flammable gas. In 1671, Robert Boyle described this reaction in more detail, but it was not until 1766 that Henry Cavendish recognized hydrogen as a true element.
In 1783, Antoine Lavoisier proposed a name for the new element, "hydrogen," after the Greek hydros for "water" and genes for "born or formed." Lavoisier recognized that when hydrogen was burned, it produced water as a byproduct, through the combination of hydrogen and oxygen in the air. Thus, the element in a sense gives birth to water. Once hydrogen was fully recognized as an element, it began to be extracted from various natural sources and used in an assortment of fields.
Hydrogen is dangerous, as most people who know about the fate of the Hindenburg are aware. It was originally used as a lifting agent in balloons and zeppelins because it was so light, but the explosive nature of the gas led to the proposal of helium as a more stable and safe replacement. Since hydrogen is so reactive, it must be handled with care to avoid unfortunate and explosive situations. Fortunately, few people work directly with pure hydrogen, and those who do are carefully trained.
Atomic Number: 1
Atomic Weight: 1.00794
Melting Point: 13.81 K (-259.34° C or -434.81° F)
Boiling Point: 20.28 K (-252.87°C or -423.17°F)
Density: 0.00008988 grams per cubic centimeter
Phase at Room Temperature: Gas
Element Classification: Non-metal
Period Number: 1
Hydrogen is an excellent fuel. This is because its calorific value is very high which means that it produces large amount of energy on combustion. Hydrogen fuel cell is an electrochemical cell that produces electricity from hydrogen and oxygen. It is considered as a clean environment friendly fuel as it produces only water vapor as end product. The main uses of hydrogen fuel cells are as power resources for remote locations like submarines, remote weather stations, spacecrafts, etc. Liquid hydrogen is used as fuels in rockets. Deuterium, also known as heavy hydrogen, is an isotope of hydrogen and is used as a fuel in nuclear reactors for nuclear fusion reaction.
Due to its light weight, one of the key uses of hydrogen gas is in the balloons. Today, meteorologists use it in meteorological balloons or weather balloons. These balloons carry necessary instruments high up in the air in order to record some vital information related to atmospheric conditions. During World War I, it was used in balloon airships or dirigibles but now it is no longer used as it is highly combustible in nature.
There are a wide range of industrial uses of hydrogen in chemical industry, food industry, paint industry, fertilizer industry and so on. In food industry, hydrogen is used to manufacture hydrogenated vegetable oils like butter, margarine, etc. In this process, vegetable oils are chemically treated with hydrogen in presence of nickel as a catalyst to produce the solidified fatty substances. In petrochemical industry, it is used for refining crude oils. In welding industry, the welding torches that are used for melting steel consist of hydrogen. In chemical industry, it is used as a reducing agent for extraction of metals from their ores. For instance, tungsten which is mined in the form of tungsten oxide is treated with hydrogen to obtain pure tungsten and water.
Hydrogen is required for the manufacturing of many important chemical compounds. One of them is ammonia which is used for making fertilizers. It is used for making different types of important acids such as hydrochloric acid as well as bases. It is used for production of methyl alcohol which is required in paints, varnishes, inks, etc. Another important compound of hydrogen is hydrogen peroxide. We find so many uses of hydrogen peroxide in our homes. It has amazing medicinal values and is an integral part of our first aid box. It can be used to heal up small cuts and wounds and as a disinfectant on toenail fungus. It can be diluted with water and used as mouthwash to kill germs and bacteria, heal canker sores and for teeth whitening. There are some non medical hydrogen peroxide uses as well. It is used as a bleaching agent for cleaning homes, for stain removal from clothes and as pest controller in gardens.
These are some of the important uses of hydrogen. Hope you enjoyed reading them. However, one thing has to be kept in mind that hydrogen in its pure form is a potentially dangerous substance and need to be handled with great care. If it leaks out from its storage container into the open air, it can cause outbreak of fire. So it has to be stored properly with adequate precautionary measures.
Hydrogen can be produced from diverse domestic resources, with the potential for near-zero greenhouse gas emissions. Once produced, it generates power without exhaust emissions in fuel cells. It holds promise for economic growth in both the stationary and transportation energy sectors.
The United States imports more than 60% of its petroleum, two-thirds of which is used to fuel vehicles in the form of gasoline and diesel. The demand for petroleum imports is increasing. With much of the worldwide petroleum reserves located in politically volatile countries, the United States is vulnerable to supply disruptions.
No matter how efficient conventional vehicles become, some of the gasoline and diesel needed to fuel them will need to be imported. Hydrogen can be produced domestically from resources such as natural gas, coal, solar energy, wind, biomass, and nuclear energy. Used to power highly efficient fuel cell vehicles, hydrogen holds the promise of an end to the nation's "addiction to oil."
About half of the U.S. population lives in areas where air pollution levels are high enough to negatively impact public health or the environment. Emissions from gasoline and diesel vehicles—such as nitrogen oxides, hydrocarbons, and particulate matter—are a major source of this pollution. Hydrogen-powered fuel cell vehicles emit none of these harmful substances. Their only emission is H2O—water.
The environmental and health benefits are even greater when hydrogen is produced from low- or zero-emission sources such as solar, wind, and nuclear energy and fossil fuels with advanced emission controls and carbon sequestration. Because the transportation sector accounts for about one third of U.S. carbon dioxide emissions, which contribute to climate change, using these sources to produce hydrogen for transportation can slash greenhouse gas emissions.
The potential market for hydrogen vehicles is enormous, but the opportunities don't stop there. Hydrogen and fuel cells can power stationary applications such as backup generators, and grid electricity production. They can also compensate for the intermittency of renewable energy production. For example, wind generators can produce hydrogen when winds are high and electricity demand is low. When the wind slackens or electricity demand peaks, fuel cells consume the stored hydrogen to provide grid electricity.
The United States stands to profit from hydrogen technologies. A recent study projected global annual demand for stationary and transportation fuel cell products to reach $46 billion by 2011 and more than $2.5 trillion by 2021. Government and industry investment in hydrogen and fuel cell technologies has positioned the United States as a leader in this rapidly growing market.
Hydrogen is the most abundant element in the universe; however, here on the surface of the Earth, pure hydrogen gas is relatively rare. That's because hydrogen gas -- which is usually found in molecular form, with two hydrogen atoms bound together to form H2 -- is so light that, if not contained, it will rise rapidly to the top of the Earth's atmosphere and escape into space. Most hydrogen on the Earth's surface is bound together with other types of atoms as molecules that form various substances. For example, H2O, better known as water, and CH4, also known as methane, both contain hydrogen molecules. Before it can be used as a fuel, the hydrogen must first be extracted from these substances and then contained, usually in highly compressed liquid form.
Are there dangers associated with pure hydrogen? To put it simply, yes. When liquid hydrogen is stored in tanks, it's relatively safe, but if it escapes there are associated hazards.
Topping the list of concerns is hydrogen burns. In the presence of an oxidizer -- oxygen is a good one -- hydrogen can catch fire, sometimes explosively, and it burns more easily than gasoline does. According to the American National Standards Institute, hydrogen requires only one 10th as much energy to ignite as gasoline does. A spark of static electricity from a person's finger is enough to set it off. Ideally, no oxygen should be present in the liquid hydrogen tanks in a fuel cell vehicle, but trace amounts of air may contaminate the hydrogen supply. If the hydrogen should escape, it will immediately come into contact with the oxygen in air.
Another concern is that hydrogen flames are nearly invisible. When hydrogen catches fire, the flames are so dim and hard to see that they're both hard to avoid and hard to fight.
Next, there's the potential for hydrogen to asphyxiate people. Hydrogen isn't poisonous, but if you should breathe pure hydrogen you could die of asphyxiation simply because you'll be deprived of oxygen. Worse, you won't necessarily know that you're breathing hydrogen because it's invisible, odorless and flavorless -- much like oxygen.
The final concern that we want to mention here is that liquid hydrogen is cold. Because it's highly compressed, liquid hydrogen is extremely cold. If it should escape from its tank and come in contact with skin it can cause severe frostbite.
Now that you know about the dangers of hydrogen as a fuel source, should you be terrified by the prospect of having a tank full of it in your car? Not necessarily. Because hydrogen gas is so light, it disperses rapidly, mixing with the surrounding air and rapidly rising through it. Although pure hydrogen ignites quite easily, in reality, this diluted hydrogen mixture is no more likely to catch fire than gasoline is. And because it rises it isn't likely to remain near the ground, where it's most likely to harm people.
The most famous hydrogen fire in history was probably the explosion of the German airship Hindenburg in 1937. No one is exactly sure how the fire started -- there are a few theories -- but the Hindenburg contained a large quantity of hydrogen, which burst into flame along with the airship's skin. Of the 97 passengers and crewmembers on board the Hindenburg, 35 died. This harmed the reputation of hydrogen for many decades and most likely slowed its use as a fuel; however, there's no evidence that any of the victims were killed by the hydrogen fire itself. Most died when they panicked and jumped out of the airship. The rest were killed when the fire spread to the engines, as result of the airship's burning skin. The hydrogen, meanwhile, rose above the passengers and crewmembers, keeping the hydrogen fire above the mayhem happening below.
Because a hydrogen fire doesn't radiate as much heat as most fires do, it is less likely to cause secondary fires. This doesn't mean that the hydrogen fire wouldn't burn you if you touched it -- it's still plenty hot -- but it's less likely to spread. As for the hydrogen being odorless and undetectable, this can be offset to some extent by the addition of odorants to hydrogen fuel, giving the hydrogen an artificial yet detectable smell. As the hydrogen disperses the odorant won't necessarily travel with it, but you'll be able to determine that a hydrogen leak has occurred and take appropriate action.
As for the danger of asphyxiation -- this is really only a problem in an enclosed space, such as a garage. If a hydrogen leak occurs in the open, the rapid dispersal of hydrogen means that it's unlikely that there will be a large enough concentration of the gas to present a breathing hazard.
This doesn't mean that hydrogen shouldn't be treated with a healthy respect for its dangers, but in practice, these dangers are unlikely to be any greater than those of gasoline. In fact, with its rapid dispersal and tendency to rise, hydrogen could pose less of a threat than the fuels we use now.
Atoms of the same element with different number of neutrons are known as isotopes. Mostly all elements found in nature have different isotopes. The isotopes have similar chemical properties of the element, but differ in their physical properties from their elements. Let us now go into the details of different isotopes of hydrogen.
There are three isotopes of hydrogen that are naturally occurring isotopes. Isotopes of hydrogen atoms are the only isotopes of an element with different names used today. The hydrogen isotopes names are protium, deuterium and tritium. Let us learn about the hydrogen isotopes in short.
Hydrogen - 1
Hydrogen - 1 or protium is also written as 1H. This hydrogen isotope is abundantly found in nature. It consists of 1 proton and no neutrons.
Hydrogen - 2
Hydrogen - 2 or deuterium is one of the hydrogen isotopes. It is also written as 2H and 'D' is also used as a symbol for deuterium. It contains one proton and one neutron in the nucleus. Deuterium is not a radioactive molecule and when water molecules are enriched with 2H it is called heavy water. This heavy water is used as a neutron moderator and coolant for nuclear reactors.
Hydrogen - 3
Hydrogen - 3 is also known as tritium that contains 1 proton and 2 neutrons in the nucleus. It is also written as 3H and sometimes symbolically referred as 'T'. This is one of the radioactive isotopes of hydrogen that decays into helium -3 through β− decay and has a half-life of 12.32 years. It was commonly used as a radiolabel in chemical and biological experiments. It is also used as a thermonuclear fusion weapon and a tracer in isotope geochemistry.
Hydrogen - 4
The hydrogen 4 or 4H is one of the most unstable isotopes of hydrogen. It contains 1 proton and 3 neutrons in the nucleus. It does not occur naturally and is synthesized by bombardment of tritium and fast-moving deuterium nuclei. It is also called quadrium.
Hydrogen - 5
Another unstable isotopes of hydrogen is 5H or hydrogen - 5. This radioactive isotope of hydrogen is synthesized by bombardment of tritium with fast-moving tritium nuclei. It contains a proton and 4 neutrons in the nucleus.
Hydrogen -6
Hydrogen 6 or 6H has 1 proton and 5 neutrons. This hydrogen isotope decays through triple neutron emission and has a half life of 3 x 10 -22 seconds.
Hydrogen - 7
Hydrogen - 7 or 7H contains 1 proton and 6 neutrons.
These are the hydrogen isotopes names of which only three hydrogen isotopes are naturally occurring. Protium and deuterium are the stable isotopes of hydrogen. Whereas, the radioactive isotopes of hydrogen are 3H, 4H, 5H, 6H and 7H.