10 most difficult metals riddlesChemistry quiz
Which metal has the highest reflectivity and thermal conductivity?
Silver is a chemical element with symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal.
What is brass composed of?
copper and iron
copper and tin
copper and zinc
copper and lead
Brass is us used for musical instruments such as horns and bells for its acoustic properties and high malleability. One type of brass, called Prince's metal (75% copper, 25% zinc), is used as an imitation of gold due to its beautiful yellow color.
In welding terminology - what does acronym MIG stand for?
Metal Inactive Gas
Metal Inert Gas
Metal Inter Gas
Metal Inertly Gas
MIG – ‘MIG’ stands for ‘Metal Inert Gas’ or ‘MAG’ (‘Metal Active Gas’ welding). This is one of the most common welding techniques – and one of the easiest to learn. MIG uses a consumable electrode and an argon-carbon dioxide shielding gas to create strong welds on both thin and thick sheets of metal.
Which naturally occurring chemical element is the densest?
The density of osmium is 22,570 kg/m3, slightly more than Iridium (22,420) and platinum (21,450). Commonly used metals are considerably less dense - the density of iron is 7,870, lead 11,340 and mercury 13,456.
What is the rarest element in the Earth's crust?
Astatine is the rarest naturally occurring element that is not a transuranic element, with the total amount in Earth's crust estimated to be less than one gram at any given time. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own radioactivity.
When and where was the idea of gold, silver and bronze medals for sport event competitors introduced?
10th century BC, Ancient Greece
3rd century AD, Ancient Rome
1904 Summer Olympics, St. Louis
1936 Summer Olympics, Berlin
The choice of metals comes from the first three Ages of Man in Greek mythology: the Golden Age, when men lived among the gods; the Silver age, where youth lasted a hundred years; and the Bronze Age, the era of heroes.
Which of these elements is not a precious metal?
Lanthanum is a chemical element with symbol La . It is a soft, ductile, silvery-white metal that tarnishes rapidly when exposed to air and is soft enough to be cut with a knife. Lanthanum does not belong to precious metals.