NIST Chemistry WebBook

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View: Search Options, Models and Tools, Special Data Collections, Documentation, Changes, Notes

General Editor P.J. Linstrom Editor Emeritus W.G. Mallard

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Last major update to the site: February 9, 2015.

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This site provides thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program.

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NIST Chemistry WebBook

Rader’s CHEM4KIDS.COM – Chemistry basics for everyone!

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So you're asking, what is chemistry? Well... Here's our best definition: Chemistry is the study of matter and the changes that take place with that matter.

Don't ask us why that matters. It just does. It matters a lot. Everything on Earth, everything in the Solar System, everything in our galaxy, and everything in the Universe is made of matter. Matter is the name that scientists have given to everything that you can touch, see, feel, or smell. Click to take a look!

That's it for the introduction. Now its up to you to click and have fun! CHEM4KIDS.COM is one of many free science sites developed by our team. You may have also used Biology4Kids, Geography4Kids, Cosmos4Kids, or Physics4Kids. We even have a math site called NumberNut.com.

If you're not into graphics like home page image above, use the search tool (powered by Google) that will check our sites for the chemistry information you need. Type in a keyword or phrase and click the search button to get started.

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Rader's CHEM4KIDS.COM - Chemistry basics for everyone!

Chemistry – Wikipedia, the free encyclopedia

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Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter.[1][2] Chemistry is chiefly concerned with atoms and molecules and their interactions and transformations, for example, the properties of the chemical bonds formed between atoms to create chemical compounds. As such, chemistry studies the involvement of electrons and various forms of energy in photochemical reactions, oxidation-reduction reactions, changes in phases of matter, and separation of mixtures. Preparation and properties of complex substances, such as alloys, polymers, biological molecules, and pharmaceutical agents are considered in specialized fields of chemistry.

Chemistry is sometimes called the central science because it bridges other natural sciences like physics, geology and biology.[3][4] Chemistry is a branch of physical science but distinct from physics.[5]

The etymology of the word chemistry has been much disputed. The history of chemistry can be traced to certain practices, known as alchemy, which had been practiced for several millennia in various parts of the world.

The word chemistry comes from the word alchemy, an earlier set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism and medicine; it is commonly thought of[by whom?] as the quest to turn lead or another common starting material into gold.[6] 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).[7] 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".

The word alchemy in turn is derived from the Arabic word al-km (). In origin, the term is borrowed from the Greek or .[8][9] This may have Egyptian origins. Many[quantify] believe that al-km is derived from the Greek , which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian.[8] Alternately, al-km may derive from , meaning "cast together".[10]

In retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. The term "chymistry", in the view of noted scientist Robert Boyle in 1661, meant the subject of the material principles of mixed bodies.[11] In 1663 the chemist Christopher Glaser described "chymistry" as a scientific art, by which one learns to dissolve bodies, and draw from them the different substances on their composition, and how to unite them again, and exalt them to a higher perfection.[12]

The 1730 definition of the word "chemistry", as used by Georg Ernst Stahl, meant the art of resolving mixed, compound, or aggregate bodies into their principles; and of composing such bodies from those principles.[13] In 1837, Jean-Baptiste Dumas considered the word "chemistry" to refer to the science concerned with the laws and effects of molecular forces.[14] This definition further evolved until, in 1947, it came to mean the science of substances: their structure, their properties, and the reactions that change them into other substances - a characterization accepted by Linus Pauling.[15] More recently, in 1998, Professor Raymond Chang broadened the definition of "chemistry" to mean the study of matter and the changes it undergoes.[16]

Early civilizations, such as the Egyptians[17]Babylonians, Indians[18] amassed practical knowledge concerning the arts of metallurgy, pottery and dyes, but didn't develop a systematic theory.

A basic chemical hypothesis first emerged in Classical Greece with the theory of four elements as propounded definitively by Aristotle stating that that fire, air, earth and water were the fundamental elements from which everything is formed as a combination. Greek atomism dates back to 440 BC, arising in works by philosophers such as Democritus and Epicurus. In 50 BC, the Roman philosopher Lucretius expanded upon the theory in his book De rerum natura (On The Nature of Things).[19][20] Unlike modern concepts of science, Greek atomism was purely philosophical in nature, with little concern for empirical observations and no concern for chemical experiments.[21]

In the Hellenistic world the art of alchemy first proliferated, mingling magic and occultism into the study of natural substances with the ultimate goal of transmuting elements into gold and discovering the elixir of eternal life.[22] Alchemy was discovered and practised widely throughout the Arab world after the Muslim conquests,[23] and from there, diffused into medieval and Renaissance Europe through Latin translations.[24]

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Chemistry - Wikipedia, the free encyclopedia

Organic chemistry – Wikipedia, the free encyclopedia

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Organic chemistry is a 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.[1][2] Study of structure includes using spectroscopy (e.g., NMR), mass spectrometry, and other physical and chemical methods to determine the chemical composition and constitution of organic compounds and materials. Study of properties includes both physical properties and chemical properties, and uses similar methods as well as methods to evaluate chemical reactivity, with the aim to understand the behavior of the organic matter in its pure form (when possible), but also in solutions, mixtures, and fabricated forms. The study of organic reactions includes probing their scope through use in preparation of target compounds (e.g., natural products, drugs, polymers, etc.) by chemical synthesis, as well as the focused study of the reactivities of individual organic molecules, both in the laboratory and via theoretical (in silico) study.

The range of chemicals studied in organic chemistry include hydrocarbons (compounds containing only carbon and hydrogen), as well as myriad compositions based always on carbon, but also containing other elements,[1][3][4] especially:

In the modern era, the range extends further into the periodic table, with main group elements, including:

In addition, much modern research focuses on organic chemistry involving further organometallics, including the lanthanides, but especially the:

Line-angle representation

Ball-and-stick representation

Space-filling representation

Finally, organic compounds form the basis of all earthly life and constitute a significant part of human endeavors in chemistry. The bonding patterns open to carbon, with its valence of fourformal single, double, and triple bonds, as well as various structures with delocalized electronsmake the array of organic compounds structurally diverse, and their range of applications enormous. They either form the basis of, or are important constituents of, many commercial products including pharmaceuticals; petrochemicals and products made from them (including lubricants, solvents, etc.); plastics; fuels and explosives; etc. As indicated, the study of organic chemistry overlaps with organometallic chemistry and biochemistry, but also with medicinal chemistry, polymer chemistry, as well as many aspects of materials science.[1]

Before the nineteenth century, chemists generally believed that compounds obtained from living organisms were endowed with a vital force that distinguished them from inorganic compounds. According to the concept of vitalism (vital force theory), organic matter was endowed with a "vital force".[5] During the first half of the nineteenth century, some of the first systematic studies of organic compounds were reported. Around 1816 Michel Chevreul started a study of soaps made from various fats and alkalis. He separated the different acids that, in combination with the alkali, produced the soap. Since these were all individual compounds, he demonstrated that it was possible to make a chemical change in various fats (which traditionally come from organic sources), producing new compounds, without "vital force". In 1828 Friedrich Whler produced the organic chemical urea (carbamide), a constituent of urine, from the inorganic ammonium cyanate NH4CNO, in what is now called the Whler synthesis. Although Whler was always cautious about claiming that he had disproved the theory of vital force, this event has often been thought of as a turning point.[5]

In 1856 William Henry Perkin, while trying to manufacture quinine, accidentally manufactured the organic dye now known as Perkin's mauve. Through its great financial success, this discovery greatly increased interest in organic chemistry.[6]

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Organic chemistry - Wikipedia, the free encyclopedia

AIPMT 2015 video solutions Chemistry Q. NO. {Q-15,Q-17} {AIPMT 2015 Q&A} BY ALLEN – Video

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AIPMT 2015 video solutions Chemistry Q. NO. {Q-15,Q-17} {AIPMT 2015 Q A} BY ALLEN
Find AIPMT 2015 Video Solution of Chemistry for Q.NO. (Q-15,Q-17) (Paper CODE-F) by ALLEN CAREER INSTITUTE. For Admission Details visit :- ALLEN Corporate Website : http://www.allen.ac.in...

By: ALLEN Career Institute

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Organic Chemistry: The Basics P16 – How To Identify The Minor and Major Resonance Contributors – Video

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Organic Chemistry: The Basics P16 - How To Identify The Minor and Major Resonance Contributors
This video shows you how to identify the minor and major resonance contributors using factors such as electronegativity, the octet rule, and size.

By: The Organic Chemistry Tutor

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Organic Chemistry: The Basics P16 - How To Identify The Minor and Major Resonance Contributors - Video

Dr. Stephen Boyd – High-Temperature Chemistry with Molten Salt Reactors – Video

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Dr. Stephen Boyd - High-Temperature Chemistry with Molten Salt Reactors
Dr. Stephen Boyd examines non-electrical applications for the high-temperature offered by small, modular, molten salt reactors. Organic Chemistry: hycrocarbons (value added-molecular streams),...

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Dr. Stephen Boyd - High-Temperature Chemistry with Molten Salt Reactors - Video

Organic Chemistry: The Basics P7 – What Are Valence Electrons? – Video

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Organic Chemistry: The Basics P7 - What Are Valence Electrons?
Have you ever wondered what are valence electrons? This video explains what exactly are valence electrons visually and how to find the number of valence electrons in an element using the periodic...

By: The Organic Chemistry Tutor

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Organic Chemistry: The Basics P7 - What Are Valence Electrons? - Video

Tom Izzo: Parallels between Spartans’ and Warriors’ team chemistry – Detroit Free Press

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USA TODAY Sports' Jeff Zillgitt and Sam Amick discuss what we can expect next after a wild Game 4 win by the Cavaliers. USA TODAY Sports

Michigan State head coach Tom Izzo watches warm-ups before Game 1 of the NBA Finals between the Warriors and Cavaliers in Oakland on June 1, 2017.(Photo: Marcio Jose Sanchez, AP)

EAST LANSING Tom Izzo has bounced from the West Coast to the Midwest the past few weeks, following the NBA Finals from San Francisco to Cleveland.

The travel allowed him to watch Draymond Greenof the Golden State Warriors, hisformer star pupil at Michigan State. But Izzo also sees parallels between this Warriors team and what he believes his Spartans can be this winter.

Back in March, we made a couple decisions that were tough decisions about what direction we wanted to go with a couple of key recruits. We dont want to screw up the chemistry we got right now, Izzo said Friday on WVFN-AM730 in Lansing. I think chemistry is very valuable. When I get out to Golden State and, after the game, Im in the family room and in the hallway with all the players, its an unbelievable collection of guys who get along. I mean, youre talking some pretty good players (Andre) Iguodalas a kid, (David) West that are coming off the bench. Draymond, the sacrifices he made for Kevin Durant.

Winning is a priority there. I think those are the kind of guys weve got.

One of the recruits Izzo likely alluded to wasSaginaw native Brian Bowen, whose prolonged recruitment took some dramatic turns over the past few months since his official visit to Breslin Center on Jan. 29. MSU was one five finalists for the five-star forward, along with Arizona, Texas, Creighton and North Carolina State.

Then everyone waited. And things changed.

The Spartans, by Izzos comments, began to distance themselves. Miles Bridges decided to return to MSU for his sophomore season, taking up a spot and plenty of shots for next season. And at Arizona, guard Allonzo Trier stayed and bypassed the NBA draft. By the end, none of Bowens top five were his destination. He picked Louisville over Oregon, DePaul and the others.

With five-star big man Brandon McCoy picking UNLV and high-rising guard Mark Smith staying at home in Illinois, MSU still has one scholarship left for this fall. Izzo is comfortable banking it until 2018.

Sometimes, you get too many stars and then you got chemistry issues, Izzo said. I think were pretty much almost 99.9% set how we are. If there was a transfer that had to sit out, maybe wed look at that. But we think that next year could be a big recruiting class, and we want to make sure we have the scholarships for that, too.

Contact Chris Solari:csolari@freepress.com. Follow him on Twitter@chrissolari. Download our Spartans Xtra app for free onAppleandAndroiddevices!

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Tom Izzo: Parallels between Spartans' and Warriors' team chemistry - Detroit Free Press