[Solved] Balloons expand when they are heated because A) of the additional molecules in them. B) the molecules inside are moving faster. C) the molecules inside become more massive. D) the molecules inside expand when they are heated. E) Nonsense-- balloons don't expand when they are heated. Refractory Period: A time period following an action or physiological event during which a second action or event cannot be initiated. Erotic Plasticity: The degree to which an individual's sex drive can be changed by societal or environmental factors. Sexual Orientation: An inherent or immutable enduring emotional, romantic, or sexual attraction to other people. Refractory Period: A phase right after being stimulated in which a muscle or nerve cannot respond to additional stimulation.