Question: Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angular momentum proved beyond the Bohr model. The correct quantization rules for electrons in which the energy reduces to the Bohr model equation in the case of the hydrogen atom were given by Heisenberg's matrix mechanics in 1925 and the Schrodinger wave equation in 1926: the reduced Planck constant remains the fundamental quantum of angular momentum. In modern terms, if J is the total angular momentum of a system with rotational invariance, and Jz the angular momentum measured along any given direction, these quantities can only take on the values
Is there an answer to this question: Who introduced the reduced Planck constant?

Answer: Bohr

Question: In mid-1969, Idris travelled abroad to spend the summer in Turkey and Greece. Gaddafi's Free Officers recognized this as their chance to overthrow the monarchy, initiating "Operation Jerusalem". On 1 September, they occupied airports, police depots, radio stations and government offices in Tripoli and Benghazi. Gaddafi took control of the Berka barracks in Benghazi, while Omar Meheisha occupied Tripoli barracks and Jalloud seized the city's anti-aircraft batteries. Khweldi Hameidi was sent to arrest crown prince Sayyid Hasan ar-Rida al-Mahdi as-Sanussi, and force him to relinquish his claim to the throne. They met no serious resistance, and wielded little violence against the monarchists.
Is there an answer to this question: What was Gaddafi's coup called?

Answer: Operation Jerusalem

Question: A browser extension is a computer program that extends the functionality of a web browser. Every major web browser supports the development of browser extensions.
Is there an answer to this question: What happens when a computer program is created?

Answer: unanswerable

Question: Each play constitutes a down. The offence must advance the ball at least ten yards towards the opponents' goal line within three downs or forfeit the ball to their opponents. Once ten yards have been gained the offence gains a new set of three downs (rather than the four downs given in American football). Downs do not accumulate. If the offensive team completes 10 yards on their first play, they lose the other two downs and are granted another set of three. If a team fails to gain ten yards in two downs they usually punt the ball on third down or try to kick a field goal (see below), depending on their position on the field. The team may, however use its third down in an attempt to advance the ball and gain a cumulative 10 yards.
Is there an answer to this question: What can a team use its 10 yards to gain?

Answer:
unanswerable