What astronomical unit for distance is derived from the parallax of one second of arc? Yesterday's question was "What is the maximum number of covalent bonds between any 2 carbon atoms? " The answer was 3.

What is the maximum number of covalent bonds between any 2 carbon atoms? Yesterday's question was "Name all of the following 4 proteins that are soluble in water: collagen; hemoglobin; insulin; DNA polymerase. " The answer was Hemoglobin, insulin, and DNA polymerase, or all but collagen.

Name all of the following 4 proteins that are soluble in water: collagen; hemoglobin; insulin; DNA polymerase. Yesterday's question was "J. J. Thomson primarily used what instrument to discover electrons?" The answer was a cathode ray tube.

J. J. Thomson primarily used what instrument to discover electrons? Friday's question was "What basic force of the universe most directly functions to keep the nucleus of an atom together?" The answer was strong force.