From today's featured article
|
Heavy metals are metals with relatively high densities, atomic weights, or atomic numbers, depending on the context. They are usually the denser metals in metallurgy, or the metals with higher atomic numbers in physics, whereas chemists distinguish heavy metals by their chemical behaviour. Heavy metals tend to be less chemically reactive than light metals such as sodium, magnesium, and aluminium. The earliest known metals are heavy metals, including common metals such as iron, copper, and tin, and precious metals such as silver, gold, and platinum. Less familiar metals such as gallium, hafnium, and thallium are also heavy metals, as are the essential nutrients cobalt and zinc. Some are toxic in larger amounts or certain forms (silver and indium, for example); others, like cadmium, mercury, and lead, are highly poisonous. Sources of heavy metal poisoning may include mining and industrial waste, agricultural runoff, occupational exposure, paints and treated timber. Heavy metals are relatively scarce in the Earth's crust, but are present in many manufactured products. (Full article...)
|
Did you know...
|
Todd McKenney and Nancye Hayes
- ... that Six Dance Lessons in Six Weeks, starring Todd McKenney (pictured waltzing with Nancye Hayes) in his first non-musical role, is the "most successful" play in the Ensemble Theatre's 58-year history?
- ... that seeking to challenge both Fatah and Hamas, five left-wing factions united to jointly contest the 2016 Palestinian local elections, which have since been postponed?
- ... that the auction in 1973 of 50 pop art works from the collection of Robert Scull was viewed by the art establishment as the "nouveaux riches cashing in"?
- ... that the Güney Waterfall, a natural monument, was reestablished 50 m (160 ft) to one side after a landslide swept away its original location?
- ... that the setting of Grand Theft Auto: Vice City is heavily based on the city of Miami?
- ... that Harry Norwitch served five terms on Philadelphia's City Council but quit his race for re-election in 1967, calling the Democratic party machine "self-serving"?
- ... that the closest relative of the Caribbean sea slug Pleurobranchus areolatus is Pleurobranchus varians from the central Pacific?
- ... that "eloquent" Holbrook, "popular" Humble, ex-Congregationalist Miller, and Pilling who feared "plottings", were all vicars of St Mark's, Huddersfield, England?
|
|
|
In the news
|
Leonard Cohen
|
On this day...
|
|
|