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This is an index of lists of molecules (i.e. by year, number of atoms, etc.). Millions of molecules have existed in the universe since before the formation of Earth. Three of them, carbon dioxide , water and oxygen were necessary for the growth of life.
Water and other volatiles probably comprise much of the internal structures of Uranus and Neptune and the water in the deeper layers may be in the form of ionic water in which the molecules break down into a soup of hydrogen and oxygen ions, and deeper still as superionic water in which the oxygen crystallizes, but the hydrogen ions float about ...
A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. Because of water content, the human body contains more oxygen by mass than any other element, but more hydrogen by atom ...
The most known chemical elements whose covalent combinations make up most biological molecules on Earth. [2] All of these elements are nonmetals. In animals in general, the four elements—C, H, N, and O—compose about 96% of the weight, and major minerals (macrominerals) and minor minerals (also called trace elements) compose the remainder. [1]
At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft. [44] The metastable molecule tetraoxygen (O 4) was discovered in 2001, [45] [46] and was assumed to exist in one of the six phases of solid oxygen. It was proven in 2006 that this phase, created by pressurizing O 2 to 20 GPa, is in fact a ...
The Roman water god, Neptune, was almost identical to Poseidon. Water deity; Water (classical element) – One of four primary substances in antiquity; Holy water – Water blessed by a religious figure; Adam's ale – Colloquial allusion to water; Water sports ) List of water sports. Swimming – Water-based sport