Problem: Since at least the time of the Ancient Greeks, a proportion of Jews have assimilated into the wider non-Jewish society around them, by either choice or force, ceasing to practice Judaism and losing their Jewish identity. Assimilation took place in all areas, and during all time periods, with some Jewish communities, for example the Kaifeng Jews of China, disappearing entirely. The advent of the Jewish Enlightenment of the 18th century (see Haskalah) and the subsequent emancipation of the Jewish populations of Europe and America in the 19th century, accelerated the situation, encouraging Jews to increasingly participate in, and become part of, secular society. The result has been a growing trend of assimilation, as Jews marry non-Jewish spouses and stop participating in the Jewish community.
Name a Jewish community that disappeared entirely?
The answer is the following: Kaifeng Jews of China

Problem: Compounds of hydrogen are often called hydrides, a term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a negative or anionic character, denoted H−, and is used when hydrogen forms a compound with a more electropositive element. The existence of the hydride anion, suggested by Gilbert N. Lewis in 1916 for group I and II salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing a stoichiometry quantity of hydrogen at the anode. For hydrides other than group I and II metals, the term is quite misleading, considering the low electronegativity of hydrogen. An exception in group II hydrides is BeH
2, which is polymeric. In lithium aluminium hydride, the AlH−
4 anion carries hydridic centers firmly attached to the Al(III).
 Who suggested that hydride anions existed?character does the H atom have in a hydride?
The answer is the following: Gilbert N. Lewis

Problem: Lee has said that To Kill a Mockingbird is not an autobiography, but rather an example of how an author "should write about what he knows and write truthfully". Nevertheless, several people and events from Lee's childhood parallel those of the fictional Scout. Lee's father, Amasa Coleman Lee, was an attorney, similar to Atticus Finch, and in 1919, he defended two black men accused of murder. After they were convicted, hanged and mutilated, he never tried another criminal case. Lee's father was also the editor and publisher of the Monroeville newspaper. Although more of a proponent of racial segregation than Atticus, he gradually became more liberal in his later years. Though Scout's mother died when she was a baby, Lee was 25 when her mother, Frances Cunningham Finch, died. Lee's mother was prone to a nervous condition that rendered her mentally and emotionally absent. Lee had a brother named Edwin, who—like the fictional Jem—was four years older than his sister. As in the novel, a black housekeeper came daily to care for the Lee house and family.
What titles did Lee's father maintain at the local newspaper?
The answer is the following: editor and publisher

Problem: While Knickebein was used by German crews en masse, X-Gerät use was limited to specially trained pathfinder crews. Special receivers were mounted in He 111s, with a radio mast on the bomber's fuselage. The system worked on a higher frequency (66–77 MHz, compared to Knickebein's 30–33 MHz). Transmitters on the ground sent pulses at a rate of 180 per minute. X-Gerät received and analysed the pulses, giving the pilot both visual and aural "on course" signals. Three beams intersected the beam along the He 111's flight path. The first cross-beam acted as a warning for the bomb-aimer to start the bombing-clock which he would activate only when the second cross-beam was reached. When the third cross-beam was reached the bomb aimer activated a third trigger, which stopped the first hand of the equipment's clock, with the second hand continuing. When the second hand re-aligned with the first, the bombs were released. The clock's timing mechanism was co-ordinated with the distances of the intersecting beams from the target so the target was directly below when the bomb release occurred.
When the bomber crossed the first beam the bomber-aimer did what?
The answer is the following:
start the bombing-clock