Carbon and Related Topics

Hydrogen

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Chemical element with the symbol H and atomic number 1.

Depiction of a hydrogen atom with size of central proton shown, and the atomic diameter shown as about twice the Bohr model radius (image not to scale)

Hydrogen gas is colorless and transparent, here contained in a glass ampoule.

Phase diagram of hydrogen. The temperature and pressure scales are logarithmic, so one unit corresponds to a 10x change. The left edge corresponds to 105 Pa, which is about atmospheric pressure.

Hydrogen emission spectrum lines in the visible range. These are the four visible lines of the Balmer series

NGC 604, a giant region of ionized hydrogen in the Triangulum Galaxy

Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds.

Chemical element

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Species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species.

$Estimated distribution of dark matter and dark energy in the universe. Only the fraction of the mass and energy in the universe labeled "atoms" is composed of chemical elements.$

Periodic table showing the cosmogenic origin of each element in the Big Bang, or in large or small stars. Small stars can produce certain elements up to sulfur, by the alpha process. Supernovae are needed to produce "heavy" elements (those beyond iron and nickel) rapidly by neutron buildup, in the r-process. Certain large stars slowly produce other elements heavier than iron, in the s-process; these may then be blown into space in the off-gassing of planetary nebulae

Abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, from the Big Bang. The next three elements (Li, Be, B) are rare because they are poorly synthesized in the Big Bang and also in stars. The two general trends in the remaining stellar-produced elements are: (1) an alternation of abundance in elements as they have even or odd atomic numbers (the Oddo-Harkins rule), and (2) a general decrease in abundance as elements become heavier. Iron is especially common because it represents the minimum energy nuclide that can be made by fusion of helium in supernovae.

Mendeleev's 1869 periodic table: An experiment on a system of elements. Based on their atomic weights and chemical similarities.

The history of the discovery and use of the elements began with primitive human societies that discovered native minerals like carbon, sulfur, copper and gold (though the concept of a chemical element was not yet understood).

Carbon monoxide

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Colorless, highly poisonous, odorless, tasteless, flammable gas that is slightly less dense than air.

Carbon monoxide concentrations in Northern Hemisphere spring as measured with the MOPITT instrument

Energy level scheme of the σ and π orbitals of carbon monoxide

Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond.

Organic compound

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The L -isoleucine molecule, C6H13NO2, showing features typical of organic compounds. Carbon atoms are in black, hydrogens gray, oxygens red, and nitrogen blue.

In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds.

Silicon

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Chemical element with the symbol Si and atomic number 14.

The MOSFET, also known as the MOS transistor, is the key component of the Silicon Age. It was invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959.

Silicon crystallizes in a diamond cubic crystal structure by forming sp3 hybrid orbitals.

A hydrosilylation reaction, in which Si–H is added to an unsaturated substrate

Structure of polydimethylsiloxane, the principal component of silicones

A diatom, enclosed in a silica cell wall

It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it.

Joseph Priestley is usually given priority in the discovery.

Oxygen

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Chemical element with the symbol O and atomic number 8.

Antoine Lavoisier discredited the phlogiston theory.

Robert H. Goddard and a liquid oxygen-gasoline rocket

An experiment setup for preparation of oxygen in academic laboratories

Orbital diagram, after Barrett (2002), showing the participating atomic orbitals from each oxygen atom, the molecular orbitals that result from their overlap, and the aufbau filling of the orbitals with the 12 electrons, 6 from each O atom, beginning from the lowest-energy orbitals, and resulting in covalent double-bond character from filled orbitals (and cancellation of the contributions of the pairs of σ and σ* and π and π* orbital pairs).

Liquid oxygen, temporarily suspended in a magnet owing to its paramagnetism

Space-filling model representation of dioxygen (O2) molecule

Late in a massive star's life, 16O concentrates in the O-shell, 17O in the H-shell and 18O in the He-shell.

500 million years of climate change vs. 18O

Photosynthesis splits water to liberate and fixes into sugar in what is called a Calvin cycle.

build-up in Earth's atmosphere: 1) no produced; 2) produced, but absorbed in oceans & seabed rock; 3) starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4–5) sinks filled and the gas accumulates

Hofmann electrolysis apparatus used in electrolysis of water.

Oxygen and MAPP gas compressed-gas cylinders with regulators

An oxygen concentrator in an emphysema patient's house

Low pressure pure is used in space suits.

Most commercially produced is used to smelt and/or decarburize iron.

Water is the most familiar oxygen compound.

Oxides, such as iron oxide or rust, form when oxygen combines with other elements.

The interior of the Apollo 1 Command Module. Pure at higher than normal pressure and a spark led to a fire and the loss of the Apollo 1 crew.

In this process, is injected through a high-pressure lance into molten iron, which removes sulfur impurities and excess carbon as the respective oxides, and.

Nitrogen

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Chemical element with the symbol N and atomic number 7.

The shapes of the five orbitals occupied in nitrogen. The two colours show the phase or sign of the wave function in each region. From left to right: 1s, 2s (cutaway to show internal structure), 2px, 2py, 2pz.

Table of nuclides (Segrè chart) from carbon to fluorine (including nitrogen). Orange indicates proton emission (nuclides outside the proton drip line); pink for positron emission (inverse beta decay); black for stable nuclides; blue for electron emission (beta decay); and violet for neutron emission (nuclides outside the neutron drip line). Proton number increases going up the vertical axis and neutron number going to the right on the horizontal axis.

Molecular orbital diagram of dinitrogen molecule, N2. There are five bonding orbitals and two antibonding orbitals (marked with an asterisk; orbitals involving the inner 1s electrons not shown), giving a total bond order of three.

Solid nitrogen on the plains of Sputnik Planitia on Pluto next to water ice mountains

Structure of [Ru(NH3)5(N2)]2+ (pentaamine(dinitrogen)ruthenium(II)), the first dinitrogen complex to be discovered

Mesomeric structures of borazine, (–BH–NH–)3

Standard reduction potentials for nitrogen-containing species. Top diagram shows potentials at pH 0; bottom diagram shows potentials at pH 14.

Nitrogen dioxide at −196 °C, 0 °C, 23 °C, 35 °C, and 50 °C. converts to colourless dinitrogen tetroxide at low temperatures, and reverts to at higher temperatures.

Fuming nitric acid contaminated with yellow nitrogen dioxide

Schematic representation of the flow of nitrogen compounds through a land environment

A container vehicle carrying liquid nitrogen.

(The light noble gases, helium, neon, and argon, would presumably also be more electronegative, and in fact are on the Allen scale.) Following periodic trends, its single-bond covalent radius of 71 pm is smaller than those of boron (84 pm) and carbon (76 pm), while it is larger than those of oxygen (66 pm) and fluorine (57 pm).

Charcoal

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Wood pile before covering it with turf or soil, and firing it (circa 1890)

An abandoned charcoal kiln near Walker, Arizona, USA.

Binchōtan, Japanese high grade charcoal made from ubame oak

Ogatan, charcoal briquettes made from sawdust

Charcoal for dehumidification and air purification in bathroom.

Four sticks of vine charcoal and four sticks of compressed charcoal

Two charcoal pencils in paper sheaths that are unwrapped as the pencil is used, and two charcoal pencils in wooden sheaths

Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents.