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!).
3.3 Phase Changes During an endothermic change, the system absorbs energy from its surroundings. Melting is an example of an endothermic change. One gram of ice absorbs 334 joules (J) of energy as it melts. This amount of energy is the heat of fusion for water.