User:Louise Valmoria/Sandbox: Difference between revisions
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Transition metals are usually coloured. The colour results from absorption of photons in the visible region of light. | Transition metals are usually coloured. The colour results from absorption of photons in the visible region of light. | ||
Metals that appear black absorb all wavelengths of light in the visible spectrum. Those that appear white reflect all wavelengths. Metals that appear colourless absorb light in the infrared or ultraviolet regions of the light spectrum, therefore do not appear coloured to the human eye. | Metals that appear black absorb all wavelengths of light in the visible spectrum. Those that appear white reflect all wavelengths. Metals that appear colourless absorb light in the infrared or ultraviolet regions of the light spectrum, therefore do not appear coloured to the human eye. All cations, anions and oxoanions of the representative elements are colourless. Transition metals that are coloured are those who have partially filled d orbitals. | ||
Colourless complexes of transition metals are those which have no ''d'' electrons present, for example Sc<sup>3+</sup>, or when all ''d'' orbitals are filled. It is only partially filled ''d'' orbitals that allow for colour because there is space for an electron to be promoted from the lower energy orbitals to the higher energy orbitals. An example of colours produced by some transition complexes is below. | |||
Revision as of 01:25, 14 October 2008
Theme Weeks: There are various 'world days' and events that are coming up that inspire me to get some biographies, collections of works or just some articles. Feel free to check in on this list, add your own, or collaborate with me when these articles go live.
World Poetry Day (March 21)
(A range of some of my favourites, to those who feature heavily in my library for various reasons; focus here will be on world poets as I am sure that the more famous classic poets will be already covered by fellow Citizens)
František Branislav, born 16 March 1900 in Beroun, Czechoslovakia, died 25 July 1968 in Prague. Czech poet, children's author and translator of Scandanavian works. He translated Nettenes natt (Night of all Nights) by Norwegian poet Bjorn Rongen and also wrote a study on the Swedish language.
Works[1]
Poetry: Bílý kruh (1924), Na rozcestí (1927), Větrná růžice (1930), Na houslích jara, podzimu... (1933), Věčná země (1939), Dým ke hvězdám (1940), Pozdrav Polsku (1950), Milostný nápěv (1951), Krásná láska (1952), Večer u studny (1955), Prsten na cestu (1957), Cesta přátelství (úvod a verše k fotografiím z cesty A. Novotného do SSSR, 1958), Věnec z trávy (1960), Moře (1961), Řecká sonatina (1962), Divertimento a kantiléna (1964), Sluneční kámen (1969), Ezopovy bajky (1973)
Childrens' Poetry: Píseň dětství (1952), Zlatý déšť (1955), Hliněný džbánek (1957), Zelené roky (1959), Přijďte k nám, muzikanti (1960), Naše a vaše (1960), Ratolístka (1961), Modrý oblázek (1962), Ryby, rybky, rybičky (1963), Malá říkadla (1963), Polní růžičky (1966), Hodina zvonů (výbor, 1989), Básně dětem (soub. vyd., 1971, 3 sv.)
S uzlíčkem stříbra (1947), Básně (1953), Lyrika (1957), Verše (1960), Básně (1968), Pramen pod hvězdami (1975), Tiše sním (1979), Uzlíček stříbra (1980), Z rosy a studánek (1980)
Translations: Bjorn Rongen: Noc všech nocí (1951) (English for: Night of all Nights) Bjorn Rongen was a Norwegian poet, who published Nettenes natt in 1940.
Compilations: Věrnému vojáku Jonášovi (sb. na pamět J. Jonáše, velitele české legionářské roty Nazdar, 1928, s A. Rážem a F. Hamplem), Básnický almanach 1958 (1959)
Stéphane Mallarmé (March 18, 1842 – September 9, 1898), born Étienne Mallarmé. French poet, critic and leader of the Symbolist movement with Paul Verlaine.
Works
Mallarmé, Stéphane. Igitur/ Divagations/ un Coup de Des, French & European Pubns (1976)
Bibliography
Remembering the Sound of Words: Mallarmé, Proust, Joyce, Beckett by Adam Piette (1996);
Jane Mayo Roos, Jeanine Parisier Plottel, Mary Ann Caws, and Yves Bonnetoy. A Painter's Poet: Stephane Mallarme & His Impressionist Circle (1999)
Thomas A Williams. Mallarme and the Language of Mysticism
Other things on my List
La Oreja de Van Gogh - Favourite Band, Write-A-Thon Sep 2008
Jiri Kylian - choreographer
Lots of chemical element pages ... :)
Spring Cleaning - Chemistry
Colour in transition metals.
Transition metals are usually coloured. The colour results from absorption of photons in the visible region of light.
Metals that appear black absorb all wavelengths of light in the visible spectrum. Those that appear white reflect all wavelengths. Metals that appear colourless absorb light in the infrared or ultraviolet regions of the light spectrum, therefore do not appear coloured to the human eye. All cations, anions and oxoanions of the representative elements are colourless. Transition metals that are coloured are those who have partially filled d orbitals.
Colourless complexes of transition metals are those which have no d electrons present, for example Sc3+, or when all d orbitals are filled. It is only partially filled d orbitals that allow for colour because there is space for an electron to be promoted from the lower energy orbitals to the higher energy orbitals. An example of colours produced by some transition complexes is below.
Table: Colours of the hydrated complex ions of the first transition series.[2]
(Note to self - [| this how one makes a table]
| Colour | Ions and number of 3d electrons | |||
|---|---|---|---|---|
| Colourless | Sc3+ (0) | Cu+ (10) | Zn2+ (10) | |
| Red | Co2+ (7) | Mn2+ (5) | ||
| Green | Fe2+ (6) | Ni2+ (8) | V3+ (2) | Cr3+ (3) |
| Purple | Ti3+ (1) | |||
| Violet | V2+ (3) | Cr3+ (3) | Mn3+ (4) | Fe3+ (5) |
| Blue | Cr2+ (4) | Co3+ (6) | Cu2+ (9) | |
| Yellow | [FeCl]2+ (5) |
Colour Ions and number of 3d electrons
Colourless Sc3+ (0) Cu+ (10) Zn2+ (10)
Red Co2+ (7) Mn+2 (5)
Green Fe2+ (6) Ni+2 (8) V3+ (2) dr3+ )3_
Purple Ti3+ (1)
Violet V2+ (3) Cr3+ (3) Mn3+ (4) Fe3+ )5_
Blue Cr2+ (4) Co3+ (6) Cu2+ (9)
Yellow [FeCl]2+ (5)
The energy difference Δ is called the crystal-field splitting energy. (task for self: insert simple explanation + find equations to enter)
Crystal-field splitting theory
Crystal-field theory is a theory of chemical bonding, first explored by physicists in the early 1930s in relation to the spectra of ionic crystals.
A limitation of crystal-field theory is that it cannot explain the colour spectrum of complex ions or the splitting order of all ligands.
Applications
Wavelength absorption and emission by atoms is used in spectroscopy to identify elements.
- ↑ František Branislav biography (Czech)
- ↑ Fundamentals of Chemistry, Fourth Ed.