Problem: Planck constant:

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

Who helped to give the incorrect quantization rules for electrons in 1946?
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A: unanswerable

Problem: The Israel Defense Forces is the sole military wing of the Israeli security forces, and is headed by its Chief of General Staff, the Ramatkal, subordinate to the Cabinet. The IDF consist of the army, air force and navy. It was founded during the 1948 ArabIsraeli War by consolidating paramilitary organizationschiefly the Haganahthat preceded the establishment of the state. The IDF also draws upon the resources of the Military Intelligence Directorate (Aman), which works with Mossad and Shabak. The Israel Defense Forces have been involved in several major wars and border conflicts in its short history, making it one of the most battle-trained armed forces in the world.
When was the IDF founded?
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Answer: 1948

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Ye Zhiping, the principal of Sangzao Middle School in Sangzao, one of the largest in An County, has been credited with proactive action that spared the lives of all 2,323 pupils in attendance when the earthquake happened. During a three-year period that ended in 2007, he oversaw a major overhaul of his school. During that time he obtained more than 400,000 yuan (US$60,000) from the county education department, money used to widen and strengthen concrete pillars and the balcony railing of all four storeys of his school, as well as secure its concrete floors.
How much money was used to strengthen the construction of the school?
A: 400,000 yuan

Context and question: FC Barcelona had a successful start in regional and national cups, competing in the Campionat de Catalunya and the Copa del Rey. In 1902, the club won its first trophy, the Copa Macaya, and participated in the first Copa del Rey, losing 12 to Bizcaya in the final. Hans Gamper now known as Joan Gamper became club president in 1908, finding the club in financial difficulty after not winning a competition since the Campionat de Catalunya in 1905. Club president on five separate occasions between 1908 and 1925, he spent 25 years in total at the helm. One of his main achievements was ensuring Barca acquire its own stadium and thus generate a stable income.
When did Joan Gamper become the president of the Barcelona club?
Answer: 1908

Question: Meetings for worship and study are held at Kingdom Halls, which are typically functional in character, and do not contain religious symbols. Witnesses are assigned to a congregation in whose "territory" they usually reside and attend weekly services they refer to as "meetings" as scheduled by congregation elders. The meetings are largely devoted to study of Watch Tower Society literature and the Bible. The format of the meetings is established by the religion's headquarters, and the subject matter for most meetings is the same worldwide. Congregations meet for two sessions each week comprising five distinct meetings that total about three-and-a-half hours, typically gathering mid-week (three meetings) and on the weekend (two meetings). Prior to 2009, congregations met three times each week; these meetings were condensed, with the intention that members dedicate an evening for "family worship". Gatherings are opened and closed with kingdom songs (hymns) and brief prayers. Twice each year, Witnesses from a number of congregations that form a "circuit" gather for a one-day assembly. Larger groups of congregations meet once a year for a three-day "regional convention", usually at rented stadiums or auditoriums. Their most important and solemn event is the commemoration of the "Lord's Evening Meal", or "Memorial of Christ's Death" on the date of the Jewish Passover.
Is there an answer to this question: What are Jehovah Witnesses' gatherings opened and closed with?

Answer: songs (hymns) and brief prayers

Question: Preaspirated consonants are marked by placing the aspiration modifier letter before the consonant symbol: p represents the preaspirated bilabial stop.
Is there an answer to this question: Unaspirated consonants are marked how?

Answer:
unanswerable