Water antique element

Combustion has a very long history. From antiquity up to the middle ages, fire along with earth, water, and air was considered to be one of the four basic elements in the universe. However, with the work of Antoine Lavoisier, one of the initiators of the Chemical Revolution and discoverer of the Law of Conservation of Mass (1785), its importance was reduced. In 1775-1777, Lavoisier was the first to postulate that the key to combustion was oxygen. He realized that the newly isolated constituent of air (Joseph Priestley in England and Carl Scheele in Sweden, 1772-1774) was an element he then named it and formulated a new definition of combustion, as the process of chemical reactions with oxygen. In precise, quantitative experiments he laid the foundations for the new theory, which gained wide acceptance over a relatively short period. 

The four elements of antiquity perfuse the history of Western culture. Shakespeare s Lear runs amok in the stormy rain, the rushing air, and the oak-cleaving thunderbolts of fire, nature s fretful elements . Two of his sonnets are paired in celebration of the quartet sea and land... so much of earth and water wrought , and slight air and purging fire . Literary tradition has continued to uphold the four ancient elements, which supply the organizing principle of T. S. Eliot s Quartets. 

Lavoisier delivered two shocks to the Aristotelian elements. His experiments on water led him to conclude in 1783 that it is not a simple substance at all, not properly called an element, as had always been thought . And, concerning that other fluid element of antiquity, he announced that atmospheric air is composed of two elastic fluids of different and opposite qualities , which he called mephitic air and highly respirable air . Neither water nor air, in other words, is an element. 

Phosphorus has many allotropes. The most common of these is white phosphorus, which exists in two modifications, a-P4 (cubic) and p-P4 (hexagonal). Condensation of phosphorus from the gas or liquid phases (both of which contain tetrahedral P4 molecules) gives primarily the a form, which slowly converts to the P form at temperatures above —76.9°C. During slow air oxidation, a-P4 emits a yellow-green light, an example of phosphorescence that has been known since antiquity (and is the source of the name of this element) to slow such oxidation, white phosphorus is commonly stored under water. White phosphorus was once used in matches however, its extremely high toxicity has led to its replacement by other materials, especially P4S3 and red phosphorus, which are much less toxic. 

Until a few years ago the best evidence for the antiquity of the Earth s oceans was from the >3.7 Ga water-lain sediments of the Isua greenstone belt, west Greenland. Now we think that the oceans are probably much older than this, for there are several new, but indirect, lines of evidence which point to the existence of liquid water extremely early in Earth history. Perhaps the most striking of these is the observation that some carbonaceous chon-drite meteorites display hydrothermal alteration. This means that there was water present on their parent asteroid and implies that liquid water was present even during the process of planetary accretion (Zolensky, 2005). This argument is consistent with the evidence from the distribution of volatile elements on the modern Earth (Section 5.2.2.3) which is most easily explained if there had been a liquid water ocean on Earth during impacting. 

I shall begin this account of chemistry s numerous achievements by considering the famous four so-called elements of antiquity earth, air, fire, and water. 

Before the modern model of the atom evolved, the concept of an element had been purely speculative. One of the definitions of an element belongs to Aristotle, one of the greatest philosophers of antiquity, who wrote Elements are simple substances of which the universe is composed and one of which cannot be separated into the other. Aristotle held that there is one primary matter and four fundamental qualities heat and coldness, dryness and wetness. Their combinations are material elements fire, water, air, and earth. According to Aristotle, all bodies are composed of these elements. Aristotle s teaching was the theoretical foundation of al-... 

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