Which was a testable idea that j. j. thomson developed through his experiments? a. atoms are the most important substances in the universe b. it is impossible to divide an atom into smaller parts. c. there are electrically neutral particles inside atoms. d. atoms contain small, negatively charged particles.

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.