Which of the following statements about planetary motion is false? a. each planet would move in a straight line without the sun's gravitational pull. b. each planet moves in a circular orbit around the sun. c. a planet's speed changes as it orbits the sun. d. each planet has a period of revolution and a period of rotation.

You are attempting to recrystallize a crude product mixture. you add the appropriate amount of hot solvent and are allowing the solution to slowly cool to room temperature. however, at room temperature no crystals have appeared, which of the following methods should be used to induce crystallization? choose all correct answers. a) place the flask in an ice bath. b) swirl the contents of the flask. c) add a small seed crystal of the desired product. d) scratch the inside of the glassware using a stir rod. it can be multiple choices