1. Louis-Jacques Thenard is credited with the co-discovery of boron. Davy discovered all of the listed elements between 1807 and 1810.
2. It is not surprising because chemistry only became a science very late in the 18th century, when Lavoisier debunked the phlogiston theory, identified oxygen, introduced quantitative methods, and gained insight into the true meaning of chemical elements. The 19th century also saw Avogadro's Hypothesis which paved the way for Cannizzaro's determination of atomic masses, in turn leading to Mendeleev's periodic table. Mendeleev published his final version with gaps in 1871, predicting that those would be filled. Indeed three of those (Sc, Ga and Ge)were discovered before the end of the century.
3. Helium was first discovered by Pierre Janssen who saw extra lines in the solar spectrum that could not be attributed to hydrogen. Radioactive radon was discovered in 1900 by Friedrich Ernst Dom as a product of uranium decay.
4. Spectra are like fingerprints. If a spectrum surfaced and did not match the catalogue of known suspects, a new "criminal"(element) was on the loose.
5. If this process could become an economically viable way of generating hydrogen, it would help alleviate many environmental problems.
6.Monazite sands are small, brown, resinous, rather heavy crystals in granitic and gneissic rocks and their detritus. They are common in parts of India, Madagascar, Florida, North Carolina, and Brazil.
7. Cerium is named after an asteroid (Ceres). Ga is derived from Gallia, which is Latin for Gaul = France. Scandium is named after Scandinavia, and hafnium from Hafnia , Latin for Copenhagen.
8. Iodine is derived from the Greek word iodes, which means violet-coloured. Bernard Courtois, while trying to extract nitrate from seaweed, added too much sulfuric acid to seaweed ash, a major raw material in saltpetre production, and obtained a violet vapour that condensed to form dark crystals. Unknowingly, he had used acid to facilitate the reduction of iodate found in kelp. He prepared numerous compounds of this new element and investigated its properties. His work was announced two years after the original experiment in 1813, and the element was later named iodine.
9. We'll start with the planets: There is
U(uranium) for Uranus; Pu(plutonium) for Pluto;
Np(neptunium) for Neptune and the least obvious one,tellurium, Te,
which is named after our planet since tellus is Latin for Earth.
Ce(cerium) is named after the asteroid Ceres and so is Pd
(palladium), named after Pallas.
Helium is named after the sun (helios; and , the Greek word for sun)
selenium is named after the moon(selene:Greek = moon).
There are three other elements with names similar or identical to those of
planetary objects but they were not named after them. Titanium was named after the
Titans of greek mythology just like Saturn's moon, Titan. The planet Mercury and its
namesake among the elements were both named after the Roman god Mercury. Finally Europa,
Jupiter's moon, was
named after the legendary girl who was wooed by Zeus in the form of a bull. (How is it that
these gods could become smelly animals and still pick up chicks?), but the element
europium was named after the continent Europe. Etymologists are not convinced that the
continent was in turn named after Europa.
10. Cl + O3 --> ClO +O2
ClO + O -> O2 + Cl
Note that Cl is recycled in the reactions, so that effectively a small amount of Cl can destroy a great deal of ozone.
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