Chemistry
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General
Bonds
- https://en.wikipedia.org/wiki/Covalent_bond
- https://en.wikipedia.org/wiki/Ionic_bond - involves the electrostatic attraction between oppositely charged ions
- https://en.wikipedia.org/wiki/Steric_effects - arise from the fact that each atom within a molecule occupies a certain amount of space. If atoms are brought too close together, there is an associated cost in energy due to overlapping electron clouds (Pauli or Born repulsion), and this may affect the molecule's preferred shape (conformation) and reactivity.
- https://en.wikipedia.org/wiki/Resonance_(chemistry) or mesomerism is a quantum superposition of wave functions built from several contributing structures (also called resonance structures or canonical forms) as a way of describing delocalized electrons within certain molecules or polyatomic ions. Each contributing structure can be represented by a Lewis structure, with only an integer number of covalent bonds between each pair of atoms within the structure. Several Lewis structures are used collectively to describe the actual molecular structure. The actual structure is an approximate intermediate between the canonical forms, but its overall energy is lower than each of the contributors. This intermediate form between different contributing structures is called a resonance hybrid. Contributing structures differ only in the position of electrons, not in the position of nuclei. Resonance is a key component of valence bond theory.
Structure
- https://en.wikipedia.org/wiki/Functional_group - specific groups of atoms or bonds within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of. However, its relative reactivity can be modified by nearby functional groups.
- https://en.wikipedia.org/wiki/Aromaticity - formally used to describe an unusually stable nature of some flat rings of atoms. These structures contain a number of double bonds that interact with each other according to certain rules. As a result of their being so stable, such rings tend to form easily, and once formed, tend to be difficult to break in chemical reactions.
- https://en.wikipedia.org/wiki/Isomer - molecules with the same chemical formula but different chemical structures. That is, isomers contain the same number of atoms of each element, but have different arrangements of their atoms in space.[1][2] Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like positional isomers, cis-trans isomers and enantiomers, etc. (see chart below). There are two main forms of isomerism: structural isomerism and stereoisomerism (spatial isomerism).
- https://en.wikipedia.org/wiki/Conformational_isomerism - a form of stereoisomerism in which the isomers can be interconverted exclusively by rotations about formally single bonds (refer to figure on single bond rotation). Such isomers are generally referred to as conformational isomers or conformers and, specifically, as rotamers. Rotations about single bonds are restricted by a rotational energy barrier which must be overcome to interconvert one conformer to another. Conformational isomerism arises when the rotation about a single bond is relatively unhindered. That is, the energy barrier must be small enough for the interconversion to occur.
Organic chemistry
- https://en.wikipedia.org/wiki/Organic_chemistry - subdiscipline involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.
Inorganic chemistry
- https://en.wikipedia.org/wiki/Inorganic_compound - traditionally viewed as being synthesized by the agency of geological systems. In contrast, organic compounds are found in biological systems
- - The colors of chemistry - This notebook documents my exploration of color theory and its applications to photochemistry. It also shows off the functionality of several Julia packages: Color.jl for color theory and colorimetry, SIUnits.jl for unitful computations, and Gadfly.jl for graph plotting.
- The Curious Case of Polywater - lol, wups
- https://en.wikipedia.org/wiki/Lipid - a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries as well as in nanotechnology.
pH
- https://en.wikipedia.org/wiki/pH - the negative log of the activity of the hydrogen ion in an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH of 7.
- https://en.wikipedia.org/wiki/Base_(chemistry) - substances that, in aqueous solution, are slippery to the touch, tastes bitter, changes the color of indicators (e.g., turns red litmus paper blue), reacts with acids to form salts, and promotes certain chemical reactions (base catalysis).
- https://en.wikipedia.org/wiki/Acid - a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals (like calcium) to form salts. Aqueous solutions of acids have a pH of less than 7. A lower pH means a higher acidity, and thus a higher concentration of positive hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic.
Reaction
- https://en.wikipedia.org/wiki/Catalysis - the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst. With a catalyst, reactions occur faster and with less energy. Because catalysts are not consumed, they are recycled. Often only tiny amounts are required.
- (portmanteau of reduction and oxidation) reactions include all chemical reactions in which atoms have their oxidation state changed; in general, redox reactions involve the transfer of electrons between species.
- https://en.wikipedia.org/wiki/Redox - reactions include all chemical reactions in which atoms have their oxidation state changed; in general, redox reactions involve the transfer of electrons between species. The term "redox" comes from two concepts involved with electron transfer: reduction and oxidation. It can be explained in simple terms: Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion. Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.
Synthesis
Substances
- https://en.wikipedia.org/wiki/Mixture - a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.
Mixtures are the one product of a mechanical blending or mixing of chemical substances like elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup. Despite that there are no chemical changes to its constituents, the physical properties of a mixture, such as its melting point, may differ from those of the components.
- https://en.wikipedia.org/wiki/Colloid - a substance in which microscopically dispersed insoluble particles are suspended throughout another substance. Sometimes the dispersed substance alone is called the colloid; the term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word suspension is contradistinguished from colloids by larger particle size). Unlike a solution, whose solute and solvent constitute only one phase, a colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). To qualify as a colloid, the mixture must be one that does not settle or would take a very long time to settle appreciably.
- https://en.wikipedia.org/wiki/Emulsion - a mixture of two or more liquids that are normally immiscible (unmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working.
- https://en.wikipedia.org/wiki/Sol_(colloid) - a colloidal suspension of very small solid particles[1] in a continuous liquid medium. Sols are quite stable and show the Tyndall effect. Examples include blood, pigmented ink, cell fluids and paint.
Compounds
Phytochemistry
- https://en.wikipedia.org/wiki/Phytochemistry - in the strict sense of the word the study of phytochemicals. These are chemicals derived from plants. In a narrower sense the terms are often used to describe the large number of secondary metabolic compounds found in plants. Many of these are known to provide protection against insect attacks and plant diseases. They also exhibit a number of protective functions for human consumers.
Phytochemistry can be considered sub-fields of Botany or Chemistry. Activities can be led in botanical gardens or in the wild with the aid of Ethnobotany. The applications of the discipline can be for Pharmacognosy, or the discovery of new drugs, or as an aid for plant physiology studies.
- https://en.wikipedia.org/wiki/Phytochemical - chemical compounds that occur naturally in plants (phyto means "plant" in Greek). Some are responsible for color and other organoleptic properties, such as the deep purple of blueberries and the smell of garlic. Phytochemicals may have biological significance, for example carotenoids or flavonoids, but are not established as essential nutrients. There may be as many as 4,000 different phytochemicals.
- https://en.wikipedia.org/wiki/Terpene - a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeteria. They are often strong-smelling. They may protect the plants that produce them by deterring herbivores and by attracting predators and parasites of herbivores. Many terpenes are aromatic hydrocarbons and thus may have had a protective function. The difference between terpenes and terpenoids is that terpenes are hydrocarbons, whereas terpenoids contain additional functional groups.