Chemical substance

A chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be chemical elements, chemical compounds, ions or alloys.

Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt (sodium chloride) and refined sugar (sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical.

Chemical substances exist as solids, liquids, gases or plasma, and may change between these phases of matter with changes in temperature or pressure. Chemical reactions convert one chemical substance into another.

Chemistry

Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry includes topics such as the properties of individual atoms, how atoms form chemical bonds to create chemical compounds, the interactions of substances through intermolecular forces that give matter its general properties, and the interactions between substances through chemical reactions to form different substances.

Chemistry is sometimes called the central science because it bridges other natural sciences, including physics, geology and biology. For the differences between chemistry and physics see Comparison of chemistry and physics.

Scholars disagree about the etymology of the word chemistry. The history of chemistry can be traced to alchemy, which had been practiced for several millennia in various parts of the world.

Etymology

The word chemistry comes from the word alchemy which was an earlier set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism and medicine. It is often seen as linked to the quest to turn lead or another common starting material into gold. Alchemy, which was practiced around 330, is the study of the composition of waters, movement, growth, embodying, disembodying, drawing the spirits from bodies and bonding the spirits within bodies (Zosimos). An alchemist was called a 'chemist' in popular speech, and later the suffix "-ry" was added to this to describe the art of the chemist as "chemistry".

Drug

A drug is any substance other than food, that when inhaled, injected, smoked, consumed, absorbed via a patch on the skin or dissolved under the tongue causes a physiological change in the body.

In pharmacology, a pharmaceutical drug or medicine, is a chemical substance used to treat, cure, prevent, diagnose a disease or promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a regular basis for chronic disorders.

Pharmaceutical drugs are often classified into drug classes—groups of related drugs that have similar chemical structures, the same mechanism of action (binding to the same biological target), a related mode of action, and that are used to treat the same disease. The Anatomical Therapeutic Chemical Classification System (ATC), the most widely used drug classification system, assigns drugs a unique ATC code, which is an alphanumeric code that assigns it to specific drug classes within the ATC system. Another major classification system is the Biopharmaceutics Classification System. This classifies drugs according to their solubility and permeability or absorption properties.

Picture (song)

"Picture" is a song by American singer Kid Rock, recorded with Sheryl Crow. The song is taken from Kid Rock's album Cocky. It was released as a single by Kid Rock featuring Allison Moorer on November 12, 2002. It was the first song for the artists to be nominated for Vocal Event of The Year at the 2003 Country Music Association awards.

Song information

Kid Rock's label, Atlantic Records, was unable to obtain permission from Crow's label, A&M Records, to release the original version as a single. Therefore Atlantic Records decided to rework the song with country singer Allison Moorer (coincidentally signed to A&M's sister label Universal South Records) instead. Moorer re-recorded Crow’s vocals for the commercial release. The CD single featuring Moorer was released commercially in the US as a single on 12 November 2002.

Even though Atlantic Records was unable to obtain rights to release Crow's version as a single, mainstream, rock/alternative, and some country radio stations disregarded this and played the original version featuring Crow, while other country music radio stations played the radio edit featuring Allison Moorer instead. Because of this, Billboard credited the song on the charts as Kid Rock featuring Sheryl Crow or Allison Moorer.

Image

An image (from Latin: imago) is an artifact that depicts visual perception, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person, thus providing a depiction of it.

Characteristics

Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue or hologram. They may be captured by optical devices – such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water.

The word image is also used in the broader sense of any two-dimensional figure such as a map, a graph, a pie chart, or a painting. In this wider sense, images can also be rendered manually, such as by drawing, the art of painting, carving, rendered automatically by printing or computer graphics technology, or developed by a combination of methods, especially in a pseudo-photograph.

A volatile image is one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of a camera obscura, or a scene displayed on a cathode ray tube. A fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or any other digital process.

Picture (band)

Picture is one of the first Dutch heavy metal bands. Formed in 1979, they were especially popular in the Netherlands, Germany and Italy for their live performances, and still have a fan base in South America, Mexico and Japan.

Picture supported AC/DC, Ted Nugent and Saxon in the Netherlands. With Saxon, they did a full European tour in 1981. Later on they toured with Rose Tattoo in Germany and headlined tours in Italy and Israel.

Biography

Rinus Vreugdenhil and Laurens Bakker originally got together in 1977 and started jamming with various musicians. It wasn’t until 1979 that the classic lineup of Rinus, Laurens, Jan Bechtum, and Ronald van Prooijen came together.

Early on in Picture's career they were produced by Cat Music. They worked with manager Henk van Antwerpen and were signed to Warner Bros. Records. However, Picture felt their label were trying to steer them in a pop direction and quit the label to sign with Backdoor Records, a subsidiary of Phonogram Records.

The original line-up recorded their debut album, Picture 1 and their second effort, Heavy Metal Ears in 1980 and 1981 respectively. To begin with, they gigged throughout the Netherlands and nearby Germany and built a following. In the meantime, they started composing their own music. Jan would usually come up with the riffs, then the other members would contribute their parts. After hashing and rehashing the songs, they became the titles that would appear on the first album, Picture I.