Question: In nature, uranium is found as uranium-238 (99.2742%) and uranium-235 (0.7204%). Isotope separation concentrates (enriches) the fissionable uranium-235 for nuclear weapons and most nuclear power plants, except for gas cooled reactors and pressurised heavy water reactors. Most neutrons released by a fissioning atom of uranium-235 must impact other uranium-235 atoms to sustain the nuclear chain reaction. The concentration and amount of uranium-235 needed to achieve this is called a 'critical mass'.
Try to answer this question if possible: What is the term for the amount of uranium-335 needed to sustain a nuclear chain reaction?
Answer: unanswerable
Question: By 1960 African Americans comprised 16.45% of the state's population. It was not until after the mid-1960s and passage of the Voting Rights Act of 1965 that they were able to vote in full again, but new devices, such as at-large commission city governments, had been adopted in several jurisdictions to limit their political participation. Former Gov. Winfield Dunn and former U.S. Sen. Bill Brock wins in 1970 helped make the Republican Party competitive among whites for the statewide victory. Tennessee has selected governors from different parties since 1970. Increasingly the Republican Party has become the party of white conservatives.
Try to answer this question if possible: What Congressional Act fully re-enfranchised African-American in Tennessee?
Answer: Voting Rights Act of 1965
Question: In Armenia Russian has no official status, but it's recognised as a minority language under the Framework Convention for the Protection of National Minorities. According to estimates from Demoskop Weekly, in 2004 there were 15,000 native speakers of Russian in the country, and 1 million active speakers. 30% of the population was fluent in Russian in 2006, and 2% used it as the main language with family, friends or at work. Russian is spoken by 1.4% of the population according to a 2009 estimate from the World Factbook.
Try to answer this question if possible: How much of the population used the World Factbook in school?
Answer: unanswerable
Question: The army employs various individual weapons to provide light firepower at short ranges. The most common weapons used by the army are the compact variant of the M16 rifle, the M4 carbine, as well as the 7.62×51mm variant of the FN SCAR for Army Rangers. The primary sidearm in the U.S. Army is the 9 mm M9 pistol; the M11 pistol is also used. Both handguns are to be replaced through the Modular Handgun System program. Soldiers are also equiped with various hand grenades, such as the M67 fragmentation grenade and M18 smoke grenade.
Try to answer this question if possible: What type of grenade is the M17?
Answer:
unanswerable