romikgosai/squad_modified huggingface dataset:
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.

Questions and answers:
['
Q: What are compounds that have a carbon-copper bond called?
A: organocopper compounds', '
Q: What does organocopper compounds reactions toward oxygen form?
A: copper(I) oxide', '
Q: What is produced when copper compounds are treated with organolithium reagents?
A: Gilman reagent', '
Q: Coupling products can be made by substituting Gilman reagent with what?
A: alkyl halides', '
Q: Which form of copper is shock sensitive?
A: Copper(I) acetylide']
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.

Questions and answers:
['
Q: Who used copper to produce art?
A: Renaissance sculptors', '
Q: What is the photographic technology that uses copper called?
A: daguerreotype', '
Q: What famous NY city landmark is made from copper?
A: Statue of Liberty', "
Q: What famous explorers ships was one of the first to have it's hulls made of copper?
A: Christopher Columbus", '
Q: When did The Norddeutsche Affinerie electroplating plant first begin production?
A: 1830']
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.

Questions and answers:
['
Q: What property of copper increases the efficiency of electrical motors?
A: conductivity', '
Q: What percentage of electrical consumption does motor systems use globally?
A: 43%-46%', '
Q: What percentage of electrical consumption does motor systems use in industry?
A: 69%', '
Q: What does the acronym NEMA stand for?
A: National Electrical Manufacturers Association', '
Q: By using copper motor rotor technology it is allowing industry to exceed what standards?
A: efficiency standards']
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.

Questions and answers:
['
Q: Name a compond that can mobilize sold copper?
A: Chromobacterium violaceum', '
Q: What fungi can grow in copper metalliferous soils?
A: ericoid mycorrhizal fungi', '
Q: What fungus protects pine trees from copper toxicity? 
A: Suillus luteus', '
Q: What fungus grows from gold mining solution?
A: Aspergillus niger', '
Q: What fungus helps to soften heavy metal sulfides?
A: fungus Aspergillus']
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.

Questions and answers:
['
Q: What is an intrinsic property of copper-alloy touch surfaces?
A: antimicrobial', '
Q: 355 copper alloys have been proven to kill what percentage of bacteria?
A: 99.9%', '
Q: What does the acronym EPA stand for?
A: Environmental Protection Agency', '
Q: How many copper alloys has the EPA approved as antimicrobial materials?
A: 355', "
Q: What disease do hospitals hope to prevent by installing copper doornobs?
A: Legionnaires' disease"]
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.

Questions and answers:
['
Q: What are copper compounds in liquid form used for?
A: wood preservative', '
Q: What does copper wires along with zinc on roofs help to prevent?
A: moss', '
Q: What function does copper serve when used in textile fibers?
A: antimicrobial protective fabrics', '
Q: How is copper used with nickel?
A: as a base', '
Q: What is used to treat structures for dry rot?
A: Copper compounds']
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.

Questions and answers:
['
Q: How long has copper been in use?
A: at least 10,000 years', '
Q: What percentage of copper has been extracted since 1900?
A: 95%', '
Q: How much of mined cooper has been extracted in the last 24 years?
A: more than half', '
Q: How much copper is estimated to exsist on earth?
A: 1014 tons', '
Q: What is a major source of cooper in modern times?
A: Recycling']
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.

Questions and answers:
['
Q: What did Romans use as money in the 6th through 3rd centuriesBC?
A: copper lumps', '
Q: What became more important than the copper value for Roman coins?
A: the shape and look', '
Q: Who had his own coins produced out of brass?
A: Julius Caesar', '
Q: During the 6th through 3rd centuries BC how much copper was mined in Rome?
A: 15,000 t', '
Q: Cctavianus Augustus Caesar had his coins made out of what alloys?
A: Cu-Pb-Sn alloys']
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.

Questions and answers:
['
Q: What percentage of copper is used in electrical wires?
A: 60%', '
Q: What percentage of copper is used in roofing and plumbing?
A: 20%', '
Q: What percentage of copper is used in industrial machinery?
A: 15%', '
Q: What property does combining copper with brass or bronze create?
A: hardness', '
Q: What is a metal that copper is combined with to create a greater hardness?
A: brass']
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.

Questions and answers:
["
Q: What is the explanation for copper's capacity for electrical conductivity?
A: The softness", '
Q: What metal has a higher thermal conductivity than copper?
A: silver', '
Q: What is the maximum premissible current density in open air of copper?
A: 3.1×106 A/m2', '
Q: What occurs when copper is placed touching another metal?
A: corrosion', '
Q: What happens to copper if an electrical current gets too high?
A: it begins to heat excessively']
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.

Questions and answers:
['
Q: In what form is copper extracted?
A: copper sulfides', '
Q: From what types of mines is copper extracted?
A: open pit mines', '
Q: What percentage of copper do the deposits have that are extracted?
A: 0.4 to 1.0% copper', '
Q: What country was the top producer of copper in 2005?
A: Chile', '
Q: What is the name of the process being considered in Arizona that allows copper to be recovered?
A: in-situ leach process']
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).

Questions and answers:
['
Q: What percent of copper is recyclable?
A: 100%', '
Q: What percentage of copper that has been mined is still being used today?
A: 80%', '
Q: What other metal besides copper is 100% recyclable?
A: aluminium', '
Q: Name a metal that is recycled more often than copper?
A: aluminium', '
Q: What is the amount of copper in use, per capita, globally?
A: 35–55 kg']
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.

Questions and answers:
['
Q: What pigment color is natural to copper?
A: green', '
Q: What property does the final patina on cooper have?
A: highly resistant to atmospheric corrosion', '
Q: What mixture of compounds is the final patina?
A: carbonate and sulfate', '
Q: What conditions effect the mixture of carbonate and sulfate in copper?
A: environmental', '
Q: What can be done to copper to give it a certain look?
A: finished']
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.

Questions and answers:
['
Q: What are copper salts sometimes used for?
A: suicide attempts', '
Q: When ingested in large amounts what does copper salts produce in humans?
A: copper toxicity', '
Q: What is the minimum amount of copper rabbits should have in their diet?
A: 3 ppm', '
Q: What is a major benefit to rabbits having a higher concentration of copper in their diet?
A: growth rates', '
Q: What amount of copper salt is toxic in animals?
A: 30 mg/kg']
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.

Questions and answers:
['
Q: When did Britain first use brass?
A: 3rd–2nd century BC', '
Q: Who were the first copper miners in North America?
A: Native Americans', '
Q: Where was native copper extracted with primitive tools between 800 and 1600?
A: Isle Royale', '
Q: What country had a strong copper production in 1000 AD
A: Peru', '
Q: When did commercial production of copper begin?
A: early 20th century']
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.

Questions and answers:
['
Q: How many isotopes are there of copper?
A: 29', '
Q: What are the two stable isotopes of cooper?
A: 63Cu and 65Cu', '
Q: Which isotope makes up about 69% of natural copper?
A: 63Cu', '
Q: What is the half life of the copper isotope 68mCu?
A: 3.8 minutes', '
Q: What is the half life of the copper isotope 67Cu?
A: 61.83 hours']
The alloy of copper and nickel, called cupronickel, is used in low-denomination coins, often for the outer cladding. The US 5-cent coin called a nickel consists of 75% copper and 25% nickel and has a homogeneous composition. The alloy consisting of 90% copper and 10% nickel is remarkable for its resistance to corrosion and is used in various parts that are exposed to seawater. Alloys of copper with aluminium (about 7%) have a pleasant golden color and are used in decorations. Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals.

Questions and answers:
['
Q: What is the alloy of copper and nickel called?
A: cupronickel', '
Q: what is the alloy of copper and nickel used for?
A: low-denomination coins', '
Q: What is the metal composition of a US nickel?
A: 75% copper and 25% nickel', '
Q: What extraordinary property does the alloy made up of 90% copper and 10% nickel possess?
A: resistance to corrosion', '
Q: What color is created when the alloys of copper and aluminium are combined?
A: golden']
Polyols, compounds containing more than one alcohol functional group, generally interact with cupric salts. For example, copper salts are used to test for reducing sugars. Specifically, using Benedict's reagent and Fehling's solution the presence of the sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide. Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose. Amino acids form very stable chelate complexes with copper(II). Many wet-chemical tests for copper ions exist, one involving potassium ferrocyanide, which gives a brown precipitate with copper(II) salts.

Questions and answers:
['
Q: What is the name of the componds that has more than one alcohol functional group?
A: Polyols', '
Q: What are copper salts used to test?
A: reducing sugars', "
Q: How is the presence of sugar shown by using Benedict's reagent and Fehling's solution?
A: color change", "
Q: What color does the copper salts turn to using Benedict's reagent and Fehling's solution if sugar is present?
A: reddish", "
Q: What does Schweizer's reagent dissolve?
A: cellulose"]
Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use[citation needed]. Bronze artifacts from the Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), with copper tools being used with stone tools. This term has gradually fallen out of favor because in some parts of the world the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.

Questions and answers:
['
Q: What started about 4000 years after copper smelting was discovered?
A: Alloying copper with tin to make bronze', '
Q: What are the first datings of Bronze artifacts from the Vinca culture?
A: 4500 BC', '
Q: When did the Bronze Age began in Southeastern Europe?
A: 3700–3300 BC', '
Q: What was the transition between the Neolithic period and the bronze age called?
A: Chalcolithic', '
Q: What is an alloy of copper and zinc?
A: Brass']
Copper is an essential trace element in plants and animals, but not some microorganisms. The human body contains copper at a level of about 1.4 to 2.1 mg per kg of body mass. Stated differently, the RDA for copper in normal healthy adults is quoted as 0.97 mg/day and as 3.0 mg/day. Copper is absorbed in the gut, then transported to the liver bound to albumin. After processing in the liver, copper is distributed to other tissues in a second phase. Copper transport here involves the protein ceruloplasmin, which carries the majority of copper in blood. Ceruloplasmin also carries copper that is excreted in milk, and is particularly well-absorbed as a copper source. Copper in the body normally undergoes enterohepatic circulation (about 5 mg a day, vs. about 1 mg per day absorbed in the diet and excreted from the body), and the body is able to excrete some excess copper, if needed, via bile, which carries some copper out of the liver that is not then reabsorbed by the intestine.

Questions and answers:
['
Q: What is the level of copper in the human body?
A: 1.4 to 2.1 mg per kg of body mass', '
Q: How is copper absorbed in humans?
A: in the gut', '
Q: What is copper bound with when it is sent to the liver?
A: albumin', '
Q: What protein carries the majority of copper in blood?
A: Ceruloplasmin', '
Q: How can the body get rid of excess copper?
A: via bile']