HYDROGEN
Hydrogen is a gaseous element, symbol H, usually classed in group 1 (or Ia) of the periodic table Hydrogen melts at –259.2° C (–434.56° F) and boils at –252.77° C (–422.986° F).
Hydrogen was confused with other gases until the British chemist Henry Cavendish demonstrated in 1766 that it was evolved by the action of sulfuric acid on metals and also showed at a later date that it was an independent substance that combined with oxygen to form water. The British chemist Joseph Priestley named the gas inflammable air in 1781, and the French chemist Antoine Laurent Lavoisier renamed it hydrogen
Properties and Occurrence
At ordinary temperatures hydrogen is a colorless, tasteless, and odorless gas, with a density of 0.089 g/liter at 0° C (32° F). It is highly flammable. Like most gaseous elements it is diatomic (its molecules contain two atoms), but it dissociates into free atoms at high temperatures. Hydrogen has a lower boiling point and melting point than any other substance except helium.
Liquid hydrogen, first obtained by the British chemist Sir James Dewar in 1898, is colorless (but light blue in thick layers) with sp.gr. 0.070. when allowed to evaporate rapidly under reduced pressure it freezes into a colorless solid.
Hydrogen is a mixture of two allotropic forms, orthohydrogen and parahydrogen, ordinary hydrogen containing about three-fourths of the ortho form and one-fourth of the para form. The melting point and boiling point of the two forms differ slightly from those of ordinary hydrogen. Practically pure parahydrogen is obtained by adsorbing ordinary hydrogen on charcoal at about –225° C (about –373° F).
Hydrogen is known to exist in three isotopic forms. The nucleus of each atom of ordinary hydrogen is composed of one proton. Deuterium, present in ordinary hydrogen to the extent of 0.02 percent, contains one proton and one neutron in the nucleus of each atom and has an atomic mass of two. Tritium , an unstable, radioactive isotope, contains one proton and two neutrons in the nucleus of each atom, and has an atomic mass of three. Both deuterium and tritium are essential components of nuclear fusion weapons, or hydrogen bombs.
Free hydrogen is found only in very small traces in the atmosphere, but solar and stellar spectra show that it is abundant in the sun and other stars, and is, in fact, the most common element in the universe. In combination with other elements it is widely distributed on the earth, where the most important and abundant compound of hydrogen is water, H2O.
Sulfur makes up almost 3 percent of the Earth’s mass. At one time, sulfur was in the layers of the Earth’s surface. Sulfur can be found in water, mineral springs, Epsom salt, and volcanoes. The sulfur in volcanoes will turn into a gas. When sulfur comes into contact with the cold air, it turns back into a solid.
The Avogadro constant is named after the early nineteenth century Italian scientist Amedeo Avogadro, who is credited (1811) with being the first to realize that the volume of a gas (strictly, of an ideal gas) is proportional to the number of atoms or molecules. The French chemist Jean Baptiste Perrin in 1909 proposed naming the constant in honor of Avogadro. American chemistry textbooks picked it up in the 1930's followed by high school textbooks starting in the 1950s.
Cost and availability of fuel is a considerable factor when dealing with nuclear power. Fission requires an element that can be easily split in a particle accelerator, such as uranium or plutonium. Fusion, on the other hand, uses isotopes of hydrogen atoms, specifically deuterium and tritium, that can be obtained from ordinary water. Uranium ores occur naturally in many parts of the world but must go through a costly purification process before used as fuel. The unprocessed ore contains approximately 99.3% uranium-238, a non-fissionable isotope of uranium, and only about 0.7% of U-235 required for fission. One hydrogen atom out of 6700 appears as deuterium, a naturally occurring isotope of hydrogen with an extra neutron, and can easily be separated from the rest. Uranium-235 is a non-renewable resource that will eventually run out, much like the fossil fuels. The abundance of deuterium and lithium provide a virtually unlimited supply of fuel for nuclear fusion. Therefore, nuclear fusion seems to be the better choice.
During the Earth’s known existence, many raise questions to a substance that is a vital necessity to our life here. Some even may claim that the start of our lives may have occurred and begun in a single drop of this universal solvent. This mysterious compound, which may have led to our development and the survival of our existence what, is it? This is H2O, or as we call it, Water. This vital life form covers over 70 percent of the Earth, and makes up about 70 percent of our body as well. We know all of this though, so what is the history behind the thing that keeps me functioning? I will need to look at: who discovered water, how it received its identity, the discovery of its chemical make-up, and its vitality to us. There is so much left uncovered about this major part of our lives. Many know of water but people don’t know what it is.
Isotopes refer to 1 of 2 or more atoms with the same atomic number but different numbers of neutrons. The atom copper has two stable isotopes. They are 63Cu and 65Cu. 63Cu has an isotope atomic mass (in atom) of 62.9295989 and a natural abundance (in atom %) of 69.17. 65Cu has an isotope atomic mass (in atom) of 64.9277929 and a natural abundance (in atom %) of 30.83.
How does the specific heat capacity of water compare to the other substances in the table?
While all atoms of the same element have the same number of protons, it is possible for atoms of one element to have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes . For example, all atoms of the element carbon have 6 protons, but while most carbon atoms have 6 neutrons, some have 7 or 8. Isotopes are named by giving the name of the element followed by the sum of the neutrons and protons in the isotope's nucl...
live on these six elements alone; even though they make up 99% of the mass, they
Hydrogen sulfide is a colorless gas with an obnoxious rotten egg odour. H2S is highly flammable, noxious and vitriolic in nature. Many petroleum and natural gas processing industries produces H2S as a by-product gaseous stream. Most H2S in the air comes from natural sulfur cycle. Exposure to H2S can lead to various health issues like burning/tearing of eyes, cough, and shortness of breath. Moderate concentration can lead to respiratory issues. So it is advisable to make use of this gas in other industrial operations.
molecules its size it would have a boiling point of -75øC and a freezing point of -125øC4.
Bruce Mattson. “Henry Cavendish 1731-1810”. History of Gas Chemistry. Updated September 25, 2001. Retrieved December 1, 2011
Since the days of Aristotle, all substances have been classified into one of three physical states. A substance having a fixed volume and shape is a solid. A substance, which has a fixed volume but not a fixed shape, is a liquid; liquids assume the shape of their container but do not necessarily fill it. A substance having neither a fixed shape nor a fixed volume is a gas; gases assume both the shape and the volume of their container. The structures of gases, and their behavior, are simpler than the structures and behavior of the two condensed phases, the solids and the liquids
The Periodic Table of Elements is commonly used today when studying elements. This table’s history begins in ancient times when Greek scientists first started discovering different elements. Over the years, many different forms of the periodic table have been made which set the basis for the modern table we use today. This table includes over 100 elements and are arranged by groups and periods. Groups being vertical columns and periods being horizontal columns. With all of the research conducted over the years and the organization of this table, it is easy to use when needed.
Hart, David. " Hydrogen: A Truly Sustainable Transport Fuel?" Frontiers in Ecology and the Environment 1.3 (2003): 138-45. Web. Kühne, Reinhart. "
Hydrogen is one of the most abundant elements on the earth. It can be found in the oceans as well as the atmosphere. Over the last few years, talk about the future of hydrogen power has grown from a whisper to a roar. The use of hydrogen is not just the burning of the gas, but of its use in a fuel cell. Fuel cells might be the device that causes the extinction of the internal combustion engine. A fuel cell is a device that produces electricity from a fuel and an oxidizer, a substance that combines with the fuel. The fuel and oxidizer react chemically at two separate electrodes to produce the direct electric current; These cells use hydrogen as the fuel and oxygen as the oxidizer. Hydrogen power could be the silver bullet to the current and future energy situation.