Maslow's Hierarchy of Needs. Definition. Maslow's hierarchy of needs is a theory of motivation and personality developed by the psychologist Abraham H. Maslow (1908â1970). Maslow's hierarchy explains human behavior in terms of basic requirements for survival and growth.
When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!).
Indicate whether heat energy is absorbed or liberated. A. Heat is absorbed when ice changes to water (melting), when water changes to water vapor (evaporation), and when ice turns directly to water vapor without passing through the liquid state (sublimation).