Hydrogen - Hydrogen Is Everywhere, The Element, Discovery And Preparation, Uses Of Hydrogen, Hydrogen Disasters
water atomic meaning liquid
Hydrogen is the chemical element of atomic number 1. Its symbol is H, it has an atomic weight of 1.008, its specific gravity at 32°F (0°C) is 0.0000899, and it melts at -434.7°F (-259.3°C). The boiling point of hydrogen is -423.2°F (-252.9°C), just above absolute zero. Boiling liquid hydrogen is the coldest substance known, with the exception of liquid helium. At room temperature, hydrogen is a colorless, odorless, tasteless gas. It consists of two stable isotopes of mass numbers 1 and 2.
Hydrogen is "number one" among the chemical elements. That is, it is the element whose atomic number is one. Its atoms are the simplest and lightest of all. A hydrogen atom contains only one electron, and it has a nucleus that consists of nothing but a proton. (A small percentage of hydrogen nuclei also contain one or two neutrons; see below.) In the periodic table, it is in a class by itself; there are no other members of its exclusive "group." It is usually placed at the top, all by itself.
Hydrogen's name is a clue to its most important position among the world's elements. It comes from the Greek hydro, meaning water, and genes, meaning born or formed. Hydrogen is a substance that gives birth to water (with a little help from oxygen). The name was coined in 1783 by the French chemist Antoine Lavoisier (1743-1794) in honor of the fact that when hydrogen burns in air it reacts with oxygen to form water, H2O.
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There are roughly 170 million billion tons of hydrogen tied up in the earth's supply of water. Hydrogen is therefore the most abundant of all elements on Earth. (Remember, there are twice as many hydrogen atoms in water as there are oxygen atoms.) Because the stars are mostly made of hydrogen, it is also the most abundant element in the universe, making up about 93% of all the atoms, and ab…
There are three isotopes of hydrogen, two stable and one radioactive. Like all isotopes, they have the same number of protons in the nucleus (in this case, one) but differing numbers of neutrons. Hydrogen is the only element whose isotopes go by their own names: protium (used only occasionally, when it is necessary to distinguish it from the others), deuterium, and tritium. Their mass numbers are …
Hydrogen is so easy to make by adding a metal to an acid that it was known as early as the late fifteenth century. Paracelsus (1493?-1541) made it by adding iron to sulfuric acid, but it wasn't until 1766 that it was recognized as a distinct substance, different from all other gases, or what were then called "airs." Henry Cavendish (1731-1810), an English chemist, gets the cre…
Hydrogen and nitrogen gases can react to form ammonia:
This reaction, called the Haber process, is used to manufacture millions of tons of ammonia every year in the United States alone, mostly for use as fertilizer. The Haber process converts nitrogen from the air, which plants cannot use, into a form (ammonia) that they can use. In order to get the biggest yield of ammonia, the reaction has …
Liquid hydrogen, combined with liquid oxygen, is the fuel that sends space shuttles into orbit. The reaction between hydrogen and oxygen to form water gives off a large amount of energy. They are useful as a rocket fuel because in their liquid forms, large quantities of them can be stored in a small space. They are very dangerous to handle, however, because unless they are kept well below their bo…
Hydrogen reacts with all the halogens to form hydrogen halides, such as hydrogen chloride HCl and hydrogen fluoride HF. These compounds are acids when dissolved in water, and are used among other things to dissolve metals and, in the case of HF, to etch glass. …
When hydrogen burns in air, it produces nothing but water vapor. It is therefore the cleanest possible, totally nonpolluting fuel. This fact has led some people to propose an energy economy based entirely on hydrogen, in which hydrogen would replace gasoline, oil, natural gas, coal, and nuclear power. The idea is that hydrogen would be prepared by the electrolysis of sea water in remote coastal ar…
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User Comments
about 1 year ago
what is hydrogen and hyrogen please tell me!!!!!!!!!!
over 3 years ago
the person that discover hydrogen was Henry Cavendish.!!!
over 3 years ago
what are 2 chemical properties of hydrgen gas?
over 3 years ago
where was Hydrogen discovered? it doesn't say on this website :(
almost 5 years ago
What is the melting point of hydrogen? it is not on your web site!!!!