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Reactivity refers to the rate at which a chemical substance tends to undergo a chemical reaction in time. In pure compounds, reactivity is regulated by the physical properties of the sample. For instance, grinding a sample to a higher specific surface area increases its reactivity. In impure compounds, the reactivity is also effected by the inclusion of contaminants. In crystalline compounds, the crystalline form can also affect reactivity. However in all cases, reactivity is primarily due to the sub-atomic properties of the compound. The reaction rate for a reactant or product in a particular reaction is defined as the amount (in moles or mass units) per unit time per unit volume that is formed or removed. ...
A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ...
A chemical reaction is a process that results in the interconversion of Chemical substances . ...
A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. ...
Crystal (disambiguation) Insulin crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ...
Causes of reactivity
In general, any time a chemical reaction occurs it is due to the chemical being able to enter a more stable state. Quantum chemistry provides the most in depth and exact understanding of the reason this occurs. Electrons exist in orbitals that are the result of solving the Schrodinger equation for specific situations. A chemical reaction is a process that results in the interconversion of Chemical substances . ...
Linus Pauling, as a pioneer of the valence bond theory, is one of the first quantum chemists. ...
Properties The electron is a fundamental subatomic particle which carries a negative electric charge. ...
Electron atomic and molecular orbitals In quantum chemistry, the molecular electronic states, i. ...
In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the time-dependence of quantum mechanical systems. ...
All things (values of the n and ml quantum numbers) being equal, the order of stability of electrons in a system from least to greatest is unpaired with no other electrons in similar orbitals, unpaired with all degenerate orbitals half filled and the most stable is a filled set of orbitals. In order to achieve one of these orders of stability, an atom will react with another atom, thereby stabilizing both atoms. For example, a lone hydrogen atom has a single electron in its 1s orbital. It becomes significantly more stable (as much as 100 kilocalories per mole, or 420 kilojoules per mole) when reacting to form H2. A quantum number is a number used to parametrise certain properties of particles or other systems in quantum mechanics. ...
General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...
A calorie is a unit of measurement for energy. ...
The mole (symbol: mol) is the SI term identifying the number of particles in a given amount of matter. ...
The joule (symbol: J) is the SI unit of energy, or work. ...
It is for this same reason that carbon will almost always form four bonds. Its ground state valence configuration is 2s2 2p2, half filled. However, the activation energy to go from half filled to fully filled p orbitals is so small, it is negligible and as such carbon will form them almost instantaneously, meanwhile the process releases a significant amount of energy (exothermic). This four equal bond configuration is called sp3 hybridization. General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ...
A chemical bond is the phenomenon of atoms being held together in molecules, crystals or in solid metal. ...
Valence is a scientific term in chemistry to describe electrons in the outermost orbital. ...
This article needs to be cleaned up to conform to a higher standard of quality. ...
Exothermic has several meanings, including: In biology, an exothermic or poikilothermic animal is one that requires external sources of heat (usually sunlight) to maintain its internal temperature: for example, reptiles. ...
four sp3-Orbitals three sp2-Orbitals In chemistry, hybridisation is the mixing of atomic orbitals belonging to a same electron shell to form new orbitals suitable for the qualitative description of atomic bonding properties. ...
Chemical kinetics and reactivity The rate of any given reaction A → products (important point is that the order is first) is governed by the equation: Order in the context of a chemical reaction is a concept of reaction kinetics, a subdiscipline of physical chemistry. ...
Rate = k[A]
where the rate is the number of moles per second consumed in the rate-determining step of the reaction, [A] is the concentration of the substance in moles per liter and k is the reaction constant which is constant for that temperature and pressure, though it is independent of concentration. The greater the reactivity of a compound the higher the value of k and the higher the rate. See also: rates (tax) A rate is a special kind of ratio, of two measurements with different units. ...
Concentration is a very common concept used in chemistry and related fields. ...
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