Is methane an element

EL-MO elements and molecules, textbook

Elements - hydrogen compounds - oxygen compounds 2.4 Important molecules and their names 38 38 Fig. 038–2: Models of elementary phosphorus Fig. 038–3: Molecules of hydrogen compounds with formula and name Fig. 038–1: Molecules of elements with formula and Name The naming of molecules does not follow a strict system. Many molecular compounds have historically determined trivial names (everyday names), and systematic names are only used to a very limited extent. In the following, the most important molecules - sorted according to compound classes - are briefly presented and their names are given. Elements For non-metals, the element name is identical to the name of the atom. If there is a risk of confusion, the designation "molecule" or "atom" must follow the name. In most cases, however, one speaks of real substances in their real - ie. molecular - manifestation. Hydrogen, the non-metals of the 2nd period and the halogens (the exception "carbon" is dealt with in Section 2.9) form diatomic molecules (H 2, O 2, N 2, F 2, Cl 2, Br 2, I 2). From the 3rd period onwards, the formation of multiple bonds is avoided in the elementary state. Single bonds form larger molecular associations. In sulfur, an odorless, yellow powder, 8 sulfur atoms combine to form a ring-shaped S 8 molecule. Phosphorus forms a tetrahedral P 4 molecule from 4 atoms. However, it has become common practice to use only the element symbol for phosphorus and sulfur. Similar to sulfur, phosphorus occurs in several forms (modifications). These modifications show different properties. This occurrence with different structures is also called allotropy. Hydrogen compounds These always obey the octet rule. However, they are usually named with trivial names tries to systematize the naming. The IUPAC (International Union of Pure and Applied Chemistry) is responsible for this systematization. Hydrogen chloride HCl is an aggressive gaseous substance. In aqueous solution one speaks of hydrochloric acid. According to IUPAC, water H 2 O is called oxidane. It is also popularly referred to as dihydrogen monoxide (DHMO), a name that has led to many joking “anti-water campaigns” over the years. In 1997, for example, Nathan Zohner, a 14-year-old student from the USA, managed to get 43 of 50 surveyed classmates to vote for a chemical ban. For the analysis of this survey, Zohner received first prize in a scientific school competition. Ammonia NH 3, a poisonous, pungent smelling gas is systematically called azane. The production of ammonia from the elements is one of the most important syntheses of the 20th century and earned the developers Fritz Haber and Carl Bosch the Nobel Prize. Ammonia can be used to produce fertilizers and explosives. Hydrazine N 2 H 4, another nitrogen compound, is used as a rocket fuel. Hydrogen sulphide - sulphane - H 2 S is a very poisonous gas that smells like rotten eggs. Methane CH 4 is the simplest organic compound and the main component of natural gas. Oxygen compounds This class of compounds is commonly referred to as oxides. If several oxides are possible for an element, the number of oxygen atoms is given with Greek prefixes - mono-, di-, tri- etc. -. Elements H 2 hydrogen F 2 fluorine Cl 2 chlorine Br 2 bromine I 2 iodine O 2 oxygen S 8 (S) sulfur N 2 nitrogen P 4 (P) phosphorus hydrogen compounds HCl hydrogen chloride aqueous solution: hydrochloric acid H 2 O water NH 3 ammonia N 2 H 4 hydrazine H 2 S hydrogen sulphide CH 4 methane Fig. 038–4: An example of joking “anti-water campaigns” P 4 molecules of white phosphorus layer lattice of red phosphorus For testing purposes only - property of the publisher öbv

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