sentence-transformers/squad huggingface dataset:
Passage: The gates of the Temple of Jerusalem used Corinthian bronze made by depletion gilding. It was most prevalent in Alexandria, where alchemy is thought to have begun. In ancient India, copper was used in the holistic medical science Ayurveda for surgical instruments and other medical equipment. Ancient Egyptians (~2400 BC) used copper for sterilizing wounds and drinking water, and later on for headaches, burns, and itching. The Baghdad Battery, with copper cylinders soldered to lead, dates back to 248 BC to AD 226 and resembles a galvanic cell, leading people to believe this was the first battery; the claim has not been verified.

Question: What material were the gates of the Temple of Jerusalem made from?

Question: How is Corinthian bronze made?

Question: Where do archeologists believe that alchemy was first practiced?

Question: What metal was used to make surgical equipment in ancient India?

Question: What is the name of the battery that was developed using copper in 248 BC?
Passage: Despite competition from other materials, copper remains the preferred electrical conductor in nearly all categories of electrical wiring with the major exception being overhead electric power transmission where aluminium is often preferred. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Electrical wiring is the most important market for the copper industry. This includes building wire, communications cable, power distribution cable, appliance wire, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors. Many electrical devices rely on copper wiring because of its multitude of inherent beneficial properties, such as its high electrical conductivity, tensile strength, ductility, creep (deformation) resistance, corrosion resistance, low thermal expansion, high thermal conductivity, solderability, and ease of installation.

Question: What metal is used most often in electrical wiring?

Question: What is the most important market for copper today?

Question: How much of mined copper is used for cables and electrical wiring?

Question: What metal are most overhead electrical wires made out of?

Question: What is one property of copper that makes it so useful in electrical wiring?
Passage: Copper is biostatic, meaning bacteria will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.

Question: What word means that bacteria won't grow on a substrate?

Question: What has pure copper been replaced with in the building of ships?

Question: Because of copper's biostatic properties where is a common use for copper?

Question: In the aquaculture industry what is copper alloys commonly used to make?

Question: Name a property that makes copper a good material to use in marine environments?
Passage: Copper, silver and gold are in group 11 of the periodic table, and they share certain attributes: they have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility and electrical conductivity. The filled d-shells in these elements do not contribute much to the interatomic interactions, which are dominated by the s-electrons through metallic bonds. Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This explains the low hardness and high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.

Question: What group of the periodic table is copper in?

Question: Name a property that copper, silver and gold have in common.

Question: What makes copper bondings weaker than other metals?

Question: How is copper normally supplied?

Question: What is a weaker form of copper than fine-grained polycrystalline?
Passage: Copper is synthesized in massive stars and is present in the Earth's crust at a concentration of about 50 parts per million (ppm), where it occurs as native copper or in minerals such as the copper sulfides chalcopyrite and chalcocite, the copper carbonates azurite and malachite, and the copper(I) oxide mineral cuprite. The largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal, with the largest described single crystal measuring 4.4×3.2×3.2 cm.

Question: What is the concentration of copper in the earths crust.

Question: How large was the biggest find of copper?

Question: What year was the largest find of copper discovered?

Question: How big is the largest copper crystal that has been found?

Question: Where was the largest mass of copper found?
Passage: In Greece, copper was known by the name chalkos (χαλκός). It was an important resource for the Romans, Greeks and other ancient peoples. In Roman times, it was known as aes Cyprium, aes being the generic Latin term for copper alloys and Cyprium from Cyprus, where much copper was mined. The phrase was simplified to cuprum, hence the English copper. Aphrodite and Venus represented copper in mythology and alchemy, because of its lustrous beauty, its ancient use in producing mirrors, and its association with Cyprus, which was sacred to the goddess. The seven heavenly bodies known to the ancients were associated with the seven metals known in antiquity, and Venus was assigned to copper.

Question: What was copper called in Greece?

Question: In what area was copper first mined?

Question: What is the Greek goddess that symbolizes copper?

Question: What is the Roman goddess that symbolizes copper?

Question: What property does copper have that links it to Aphrodite and Venus?
Passage: Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry. They are synthesized by treating copper(I) compounds with Grignard reagents, terminal alkynes or organolithium reagents; in particular, the last reaction described produces a Gilman reagent. These can undergo substitution with alkyl halides to form coupling products; as such, they are important in the field of organic synthesis. Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot-Chodkiewicz coupling and the Sonogashira coupling. Conjugate addition to enones and carbocupration of alkynes can also be achieved with organocopper compounds. Copper(I) forms a variety of weak complexes with alkenes and carbon monoxide, especially in the presence of amine ligands.

Question: What are compounds that have a carbon-copper bond called?

Question: What does organocopper compounds reactions toward oxygen form?

Question: What is produced when copper compounds are treated with organolithium reagents?

Question: Coupling products can be made by substituting Gilman reagent with what?

Question: Which form of copper is shock sensitive?
Passage: The uses of copper in art were not limited to currency: it was used by Renaissance sculptors, in photographic technology known as the daguerreotype, and the Statue of Liberty. Copper plating and copper sheathing for ships' hulls was widespread; the ships of Christopher Columbus were among the earliest to have this feature. The Norddeutsche Affinerie in Hamburg was the first modern electroplating plant starting its production in 1876. The German scientist Gottfried Osann invented powder metallurgy in 1830 while determining the metal's atomic mass; around then it was discovered that the amount and type of alloying element (e.g., tin) to copper would affect bell tones. Flash smelting was developed by Outokumpu in Finland and first applied at Harjavalta in 1949; the energy-efficient process accounts for 50% of the world's primary copper production.

Question: Who used copper to produce art?

Question: What is the photographic technology that uses copper called?

Question: What famous NY city landmark is made from copper?

Question: What famous explorers ships was one of the first to have it's hulls made of copper?

Question: When did The Norddeutsche Affinerie electroplating plant first begin production?
Passage: Copper's greater conductivity versus other metals enhances the electrical energy efficiency of motors. This is important because motors and motor-driven systems account for 43%-46% of all global electricity consumption and 69% of all electricity used by industry. Increasing the mass and cross section of copper in a coil increases the electrical energy efficiency of the motor. Copper motor rotors, a new technology designed for motor applications where energy savings are prime design objectives, are enabling general-purpose induction motors to meet and exceed National Electrical Manufacturers Association (NEMA) premium efficiency standards.

Question: What property of copper increases the efficiency of electrical motors?

Question: What percentage of electrical consumption does motor systems use globally?

Question: What percentage of electrical consumption does motor systems use in industry?

Question: What does the acronym NEMA stand for?

Question: By using copper motor rotor technology it is allowing industry to exceed what standards?
Passage: Chromobacterium violaceum and Pseudomonas fluorescens can both mobilize solid copper, as a cyanide compound. The ericoid mycorrhizal fungi associated with Calluna, Erica and Vaccinium can grow in copper metalliferous soils. The ectomycorrhizal fungus Suillus luteus protects young pine trees from copper toxicity. A sample of the fungus Aspergillus niger was found growing from gold mining solution; and was found to contain cyano metal complexes; such as gold, silver, copper iron and zinc. The fungus also plays a role in the solubilization of heavy metal sulfides.

Question: Name a compond that can mobilize sold copper?

Question: What fungi can grow in copper metalliferous soils?

Question: What fungus protects pine trees from copper toxicity?

Question: What fungus grows from gold mining solution?

Question: What fungus helps to soften heavy metal sulfides?
Passage: Copper-alloy touch surfaces have natural intrinsic properties to destroy a wide range of microorganisms (e.g., E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, and fungi). Some 355 copper alloys were proven to kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly. The United States Environmental Protection Agency (EPA) has approved the registrations of these copper alloys as "antimicrobial materials with public health benefits," which allows manufacturers to legally make claims as to the positive public health benefits of products made with registered antimicrobial copper alloys. In addition, the EPA has approved a long list of antimicrobial copper products made from these alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, shopping cart handles, etc. (for a comprehensive list of products, see: Antimicrobial copper-alloy touch surfaces#Approved products). Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in plumbing systems. Antimicrobial copper alloy products are now being installed in healthcare facilities in the U.K., Ireland, Japan, Korea, France, Denmark, and Brazil[citation needed] and in the subway transit system in Santiago, Chile, where copper-zinc alloy handrails will be installed in some 30 stations between 2011–2014.

Question: What is an intrinsic property of copper-alloy touch surfaces?

Question: 355 copper alloys have been proven to kill what percentage of bacteria?

Question: What does the acronym EPA stand for?

Question: How many copper alloys has the EPA approved as antimicrobial materials?

Question: What disease do hospitals hope to prevent by installing copper doornobs?
Passage: Copper compounds in liquid form are used as a wood preservative, particularly in treating original portion of structures during restoration of damage due to dry rot. Together with zinc, copper wires may be placed over non-conductive roofing materials to discourage the growth of moss.[citation needed] Textile fibers use copper to create antimicrobial protective fabrics, as do ceramic glazes, stained glass and musical instruments. Electroplating commonly uses copper as a base for other metals such as nickel.

Question: What are copper compounds in liquid form used for?

Question: What does copper wires along with zinc on roofs help to prevent?

Question: What function does copper serve when used in textile fibers?

Question: How is copper used with nickel?

Question: What is used to treat structures for dry rot?
Passage: Copper has been in use at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900, and more than half was extracted in only the last 24 years. As with many natural resources, the total amount of copper on Earth is vast (around 1014 tons just in the top kilometer of Earth's crust, or about 5 million years' worth at the current rate of extraction). However, only a tiny fraction of these reserves is economically viable, given present-day prices and technologies. Various estimates of existing copper reserves available for mining vary from 25 years to 60 years, depending on core assumptions such as the growth rate. Recycling is a major source of copper in the modern world. Because of these and other factors, the future of copper production and supply is the subject of much debate, including the concept of peak copper, analogous to peak oil.

Question: How long has copper been in use?

Question: What percentage of copper has been extracted since 1900?

Question: How much of mined cooper has been extracted in the last 24 years?

Question: How much copper is estimated to exsist on earth?

Question: What is a major source of cooper in modern times?
Passage: The cultural role of copper has been important, particularly in currency. Romans in the 6th through 3rd centuries BC used copper lumps as money. At first, the copper itself was valued, but gradually the shape and look of the copper became more important. Julius Caesar had his own coins made from brass, while Octavianus Augustus Caesar's coins were made from Cu-Pb-Sn alloys. With an estimated annual output of around 15,000 t, Roman copper mining and smelting activities reached a scale unsurpassed until the time of the Industrial Revolution; the provinces most intensely mined were those of Hispania, Cyprus and in Central Europe.

Question: What did Romans use as money in the 6th through 3rd centuriesBC?

Question: What became more important than the copper value for Roman coins?

Question: Who had his own coins produced out of brass?

Question: During the 6th through 3rd centuries BC how much copper was mined in Rome?

Question: Cctavianus Augustus Caesar had his coins made out of what alloys?
Passage: The major applications of copper are in electrical wires (60%), roofing and plumbing (20%) and industrial machinery (15%). Copper is mostly used as a pure metal, but when a higher hardness is required it is combined with other elements to make an alloy (5% of total use) such as brass and bronze. A small part of copper supply is used in production of compounds for nutritional supplements and fungicides in agriculture. Machining of copper is possible, although it is usually necessary to use an alloy for intricate parts to get good machinability characteristics.

Question: What percentage of copper is used in electrical wires?

Question: What percentage of copper is used in roofing and plumbing?

Question: What percentage of copper is used in industrial machinery?

Question: What property does combining copper with brass or bronze create?

Question: What is a metal that copper is combined with to create a greater hardness?
Passage: The softness of copper partly explains its high electrical conductivity (59.6×106 S/m) and thus also high thermal conductivity, which are the second highest (to silver) among pure metals at room temperature. This is because the resistivity to electron transport in metals at room temperature mostly originates from scattering of electrons on thermal vibrations of the lattice, which are relatively weak for a soft metal. The maximum permissible current density of copper in open air is approximately 3.1×106 A/m2 of cross-sectional area, above which it begins to heat excessively. As with other metals, if copper is placed against another metal, galvanic corrosion will occur.

Question: What is the explanation for copper's capacity for electrical conductivity?

Question: What metal has a higher thermal conductivity than copper?

Question: What is the maximum premissible current density in open air of copper?

Question: What occurs when copper is placed touching another metal?

Question: What happens to copper if an electrical current gets too high?
Passage: Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Examples include Chuquicamata in Chile, Bingham Canyon Mine in Utah, United States and El Chino Mine in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top mine producer of copper with at least one-third world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage.

Question: In what form is copper extracted?

Question: From what types of mines is copper extracted?

Question: What percentage of copper do the deposits have that are extracted?

Question: What country was the top producer of copper in 2005?

Question: What is the name of the process being considered in Arizona that allows copper to be recovered?
Passage: Like aluminium, copper is 100% recyclable without any loss of quality, regardless of whether it is in a raw state or contained in a manufactured product. In volume, copper is the third most recycled metal after iron and aluminium. It is estimated that 80% of the copper ever mined is still in use today. According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita).

Question: What percent of copper is recyclable?

Question: What percentage of copper that has been mined is still being used today?

Question: What other metal besides copper is 100% recyclable?

Question: Name a metal that is recycled more often than copper?

Question: What is the amount of copper in use, per capita, globally?
Passage: The metal's distinctive natural green patina has long been coveted by architects and designers. The final patina is a particularly durable layer that is highly resistant to atmospheric corrosion, thereby protecting the underlying metal against further weathering. It can be a mixture of carbonate and sulfate compounds in various amounts, depending upon environmental conditions such as sulfur-containing acid rain. Architectural copper and its alloys can also be 'finished' to embark a particular look, feel, and/or color. Finishes include mechanical surface treatments, chemical coloring, and coatings.

Question: What pigment color is natural to copper?

Question: What property does the final patina on cooper have?

Question: What mixture of compounds is the final patina?

Question: What conditions effect the mixture of carbonate and sulfate in copper?

Question: What can be done to copper to give it a certain look?
Passage: Gram quantities of various copper salts have been taken in suicide attempts and produced acute copper toxicity in humans, possibly due to redox cycling and the generation of reactive oxygen species that damage DNA. Corresponding amounts of copper salts (30 mg/kg) are toxic in animals. A minimum dietary value for healthy growth in rabbits has been reported to be at least 3 ppm in the diet. However, higher concentrations of copper (100 ppm, 200 ppm, or 500 ppm) in the diet of rabbits may favorably influence feed conversion efficiency, growth rates, and carcass dressing percentages.

Question: What are copper salts sometimes used for?

Question: When ingested in large amounts what does copper salts produce in humans?

Question: What is the minimum amount of copper rabbits should have in their diet?

Question: What is a major benefit to rabbits having a higher concentration of copper in their diet?

Question: What amount of copper salt is toxic in animals?
Passage: Britain's first use of brass occurred around the 3rd–2nd century BC. In North America, copper mining began with marginal workings by Native Americans. Native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600. Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD; it proceeded at a much slower rate on other continents. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.

Question: When did Britain first use brass?

Question: Who were the first copper miners in North America?

Question: Where was native copper extracted with primitive tools between 800 and 1600?

Question: What country had a strong copper production in 1000 AD

Question: When did commercial production of copper begin?
Passage: There are 29 isotopes of copper. 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper; they both have a spin of 3⁄2. The other isotopes are radioactive, with the most stable being 67Cu with a half-life of 61.83 hours. Seven metastable isotopes have been characterized, with 68mCu the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β−, whereas those with a mass number below 64 decay by β+. 64Cu, which has a half-life of 12.7 hours, decays both ways.

Question: How many isotopes are there of copper?

Question: What are the two stable isotopes of cooper?

Question: Which isotope makes up about 69% of natural copper?

Question: What is the half life of the copper isotope 68mCu?

Question: What is the half life of the copper isotope 67Cu?