Problem: Salts of many oxidation states of uranium are water-soluble and may be studied in aqueous solutions. The most common ionic forms are U3+ (brown-red), U4+ (green), UO+
2 (unstable), and UO2+
2 (yellow), for U(III), U(IV), U(V), and U(VI), respectively. A few solid and semi-metallic compounds such as UO and US exist for the formal oxidation state uranium(II), but no simple ions are known to exist in solution for that state. Ions of U3+ liberate hydrogen from water and are therefore considered to be highly unstable. The UO2+
2 ion represents the uranium(VI) state and is known to form compounds such as uranyl carbonate, uranyl chloride and uranyl sulfate. UO2+
2 also forms complexes with various organic chelating agents, the most commonly encountered of which is uranyl acetate.
What state isn't represented by the UO2+ 2 ion?
---
Answer: unanswerable


Problem: Traditionally the Rajputs, Jats, Meenas, Gurjars, Bhils, Rajpurohit, Charans, Yadavs, Bishnois, Sermals, PhulMali (Saini) and other tribes made a great contribution in building the state of Rajasthan. All these tribes suffered great difficulties in protecting their culture and the land. Millions of them were killed trying to protect their land. A number of Gurjars had been exterminated in Bhinmal and Ajmer areas fighting with the invaders. Bhils once ruled Kota. Meenas were rulers of Bundi and the Dhundhar region.
What tribe formerly ruled Kota?
---
Answer: Bhils


Problem: Beyoncé is believed to have first started a relationship with Jay Z after a collaboration on "'03 Bonnie & Clyde", which appeared on his seventh album The Blueprint 2: The Gift & The Curse (2002). Beyoncé appeared as Jay Z's girlfriend in the music video for the song, which would further fuel speculation of their relationship. On April 4, 2008, Beyoncé and Jay Z were married without publicity. As of April 2014, the couple have sold a combined 300 million records together. The couple are known for their private relationship, although they have appeared to become more relaxed in recent years. Beyoncé suffered a miscarriage in 2010 or 2011, describing it as "the saddest thing" she had ever endured. She returned to the studio and wrote music in order to cope with the loss. In April 2011, Beyoncé and Jay Z traveled to Paris in order to shoot the album cover for her 4, and unexpectedly became pregnant in Paris.
When were Beyonce and Jay Z married?
---
Answer:
April 4, 2008