Carbon

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Ig Nobel Prize for chemistry 2009

The 2009 chemistry prize goes to Javier Morales, Miguel Apátiga, and Victor M. Castaño (Universidad Nacional Autónoma de México) for creating diamonds from liquid — specifically from tequila.

Reference
"Growth of Diamond Films from Tequila," Javier Morales, Miguel Apatiga and Victor M. Castano, 2008, arXiv:0806.1485.

Please help

Is it possible for someone to discover a new element that would be placed between carbon and nitrogen? explain.

error in units

The units of resistivity don't come out right.

10^-8 Ohm * m
or
m Ohm * cm

the 'm' should be a 'mu', but unfortunately they both look the same in the latin alphabet.

The Great Global Warming Swindle

Here in the UK, Channel 4 just screened an interesting documentary: The Great Global Warming Swindle. Good viewing and challenges what seems to have become the accepted view that global warming is caused by man-made CO2 emissions.

beta-d-glucopyranose

hi guys
is there any way to remove the hydrogens in the mulucule below? if yes what would happen to the structure?

greenhouse gases-how IR effects moleculesof CO2

I have a midterm and it includes how infrared radiation vibrates molecules of greenhouse gases such as CO2. Could you explain this further?

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New from of carbon dioxide: amorphous

Only carbon from the Group 14 elements forms stable double bonds with oxygen under normal conditions. When frozen, carbon dioxide is known as "dry-ice". A non-molecular single-bonded crystalline form of carbon dioxide (phase V) exists at high pressure.

Amorphous forms of silica (a-SiO2) and germania (a-GeO2) are known at ambient conditions but only recently has an amorphous, silica-like form of carbon dioxide, a-CO2. This is labelled a-carbonia and made by compression of CO2 at room temperature at pressures between 40 and 48 GPa (that's a staggering 400-500 thousand atmospheres).

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The Group 14 elements

Group 14 periodicity

This article addresses the periodicity displayed by the Group 14 elements but excluding, largely, ununquadium (element 114) about which virtually nothing is known. One could predict the properties of ununquadium based upno those of the higher elements and this is left as an exercise for the reader.

Nature of the elements

The elements become increasingly metallic down the group. Carbon, at the top, is a typical non-metal while silicon is a semiconductor profoundly important to the electronics industries. Tin and lead are very metallic although one modification of tin known as grey tin has the same diamond structure as does germanium and silicon. The elements lower down the group form complexes while carbon does not. The melting points of the elements decrease down the group as the elements become increasingly metallic.

Multiple bonds

Carbon often forms multiple bonds, both with itself (as in ethene and ethyne) and with other elements such as oxygen (as in carbon dioxide and ketones). In contrast, silicon, germanium, and tin only form analogues of ethene (albeit non-planar) when the elements possess bulky substituents. While the C=C π-bond formed through the overlap of C 2p-orbitals is strong, those lower down the group are much less strong. This also explains why graphite is stable while there are no analogues of graphite lower down the group. Carbon dioxide, CO2, possesses two carbon-oxygen double bonds (O=C=O) while the corresponding silicon dioxide, SiO2, possesses an extended lattice structure. This is because the π-bond formed through the overlap of p-orbitals on carbon and oxygen is strong as the overlap is favourable, while lower down the group the π-overlap is less efficient.

Hydrides

The hydrides MX4 are known for all the elements except ununquadium although the lead compound (plumbane, PbH4) is poorly characterized. Each is a covalent molecule. The parent hydride for carbon is methane, CH4, and there is an extensive range of compounds called alkanes of the type CnH2n+2 (methane, ethane, propane, butane....). There are relatively few of the corresponding silicon hydrides (silanes) and they are spontaneously flammable. The germane GeH4 is known while the stannane SnH4, a colourless gas, decomposes to tin at about 0°C.

Halides

Two types of halide for this group are known: MX2 and MX4. The M(IV) halides dominate the top of the group while the M(II) halides dominate at the bottom. All the M(IV) halides MX4 (M = C, Si, Ge; X = F, Cl, Br, I) are all known for the three elements carbon, silicon, and germanium at the top of the group. However, as the group is descended, the stability of the M(II) state increases relative to the M(IV) state. None of the dihalides MX2 exist independently for carbon or silicon while most of the divalent halides MX2 are known for germanium in addition to the germanium tetrahalides. At the bottom of the group the most stable lead halides are PbX2 and the only known tetrahalide seems to be PbCl4 (this decomposes exothermically to PbCl2 and chlorine gas).

Oxides

Ionization Energy

ionization energies for Group 14 elements

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Bucky Balls codiscoveror Richard Smalley dies

Nobel laureate Richard Smalley, the Rice University professor who helped discover buckyballs (buckminsterfullerene, C60, the football (soccer) ball shaped form of carbon, died at the age of 62. Richard Smalley shared the 1996 Nobel Prize in chemistry with Sir Harold Kroto (Sussex) and Robert Curl (also Rice) for the identification of the new form of carbon known as buckminsterfullerene because of its similarity to Buckminster Fuller's geodesic domes. Further information: Nanotubes and Buckyballs and Smalley Research Group.

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Titan's methane springs

Lands, rivers and methane springs: latest images of Titan. Titan's atmosphere is mostly nitrogen but there is also methane and many other organic compounds.

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