Answer: Adele More information: With over 1.1 million copies sold during its debut week, Adele's "Hello" reigns well above the second track on the list - Flo Rida's "Right Round" - for the song to sell the most downloads in a single week.
Answer: Spring Equinox / Summer Solstice More information: The astronomical foundation of May Day lies in it falling almost midway between the vernal equinox (usually 20 March) and the summer solstice (usually 21 June) in the Northern Hemisphere, the part of the world where May Day festivals are often relegated to.
Answer: "Equal night" More information: Equinox translates into English as "equal night", which alludes to the fact that day and night hours are virtually the same length during these occasions.
Answer: NaCl More information: Sodium chloride (also known as salt or halite), is an ionic compound representing a 1:1 ratio of sodium and chloride ions.
