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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.
Matter organizes into various phases or states of matter depending on its constituents and external factors like pressure and temperature. Except at extreme temperatures and pressures, atoms form the three classical states of matter: solid, liquid and gas.
Atoms are the smallest neutral particles into which matter can be divided by chemical reactions. An atom consists of a small, heavy nucleus surrounded by a relatively large, light cloud of electrons. An atomic nucleus consists of 1 or more protons and 0 or more neutrons. Protons and neutrons are, in turn, made of quarks.
It is a matter of taste whether one includes the lone pair in a drawing. Lone pairs of electrons are more common for depictions that emphasize bonding, as in simple gaseous molecules, such as ammonia and nitric oxide. Nonmolecular compounds, e.g. sodium hydride, are best represented with colour-coded spheres that emphasise packing.
Atomic radii may be derived from the distances between two nuclei when the two atoms are joined in a chemical bond. The radius varies with the location of an atom on the atomic chart, the type of chemical bond, the number of neighboring atoms (coordination number) and a quantum mechanical property known as spin. [70]
Because atoms and molecules are said to be matter, it is natural to phrase the definition as: "ordinary matter is anything that is made of the same things that atoms and molecules are made of". (However, notice that one also can make from these building blocks matter that is not atoms or molecules.) Then, because electrons are leptons, and ...
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 ...
A quark (/ k w ɔːr k, k w ɑːr k /) is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. [1] All commonly observable matter is composed of up quarks, down quarks and electrons.