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Niobium: Quiz


Question 1: Niobium is used mostly in alloys, the largest part in special ________ such as that used in gas pipelines.
Stainless steelSteelCarbon steelIron

Question 2: Niobium has physical and chemical properties similar to those of the element ________, and the two are therefore difficult to distinguish.

Question 3: Niobium is able to form oxides with the ________ +5 (Nb2O5), +4 (NbO2) and +3 (Nb2O3),[26] as well as with the rarer oxidation state +2 (NbO).
OxygenHydrogenOxidation stateValence (chemistry)

Question 4: [26] Lithium niobate, which is a ________, is used extensively in mobile telephones and optical modulators, and for the manufacture of surface acoustic wave devices.
DielectricPiezoelectricityPolarization densityFerroelectricity

Question 5: Although de Marignac was able to produce tantalum-free niobium on a larger scale by 1866, it was not until the early 20th century that niobium was first used commercially, in ________ filaments.
Fluorescent lampIncandescent light bulbCompact fluorescent lampFlashtube

Question 6: It reacts with most nonmetals at high temperatures: niobium reacts with fluorine at room temperature, with ________ and hydrogen at 200 °C, and with nitrogen at 400 °C, giving products that are frequently interstitial and nonstoichiometric.

Question 7: The ________ estimates that the production increased from 38,700 metric tonnes in 2005 to 44,500 tonnes in 2006.
United States Fish and Wildlife ServiceNational Park ServiceMinerals Management ServiceUnited States Geological Survey

Question 8: The temperature stability of niobium-containing superalloys is important for its use in ________ and rocket engines.
Swing-piston engineJet engineStirling engineRocket engine nozzle

Question 9: The first step in the processing is the reaction of the oxides with ________:[32]
Hydrofluoric acidFluorineSulfuric acidHydrochloric acid

Question 10: Both are ________ by water and react with additional niobium at elevated temperatures by forming the black and highly hygroscopic niobium tetrafluoride (NbF4) and niobium tetrachloride (NbCl4).

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