Technetium
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| Electron affinity || -53 kJ/mol
Technetium () is the lightest chemical element with no stable isotope . It has atomic number 43 and is given the symbol Tc. The chemical properties of this silvery grey, crystalline transition metal are inte more
Diamond
Diamond is an allotrope of carbon . It is the hardest known natural material and the third-hardest known material after aggregated diamond nanorods and ultrahard fullerite . Its hardness and high dispersion of light make it useful for industrial applications and jewelry .
Diamon more
Slate industry in Wales
, Wales, about 1910.
The slate industry in Wales began during the Roman period when slate was used to roof the fort at Segontium , now Caernarfon . The slate industry grew slowly until the early 18th century, then expanded rapidly until the late 19th century, at which t more
Proteasome
Proteasomes are large protein complex es inside all eukaryote s and archaea , as well as in some bacteria . In eukaryotes, they are located in the nucleus and the cytoplasm .Peters JM, Franke WW, Kleinschmidt JA. (1994) Distinct 19S and 20S subcomplexes of the 26S proteasome and their more
Sun
The Sun () is the star at the center of the Solar System . It is a medium size star. The Earth and other matter (including other planet s, asteroid s, meteoroid s, comet s and dust ) orbit the Sun, which by itself accounts for about 99.8% of the solar system 's mass . Energy from the Sun, more