Nina studies an artificial heart model. The model has tubes that supply an electric current to the model. Nina switches on the current that provides an impulse to the heart. She observes that the heart contracts and relaxes. Compare this model with that of a human heart, and place the steps describing how blood flows through the human heart in order.

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