Dr. M. J. Passow  INTERMEDIATE LEVEL SCIENCE
Physical Setting Key Idea 4: Energy exists in many forms, and when these forms change, energy is conserved.
4.1  Describe the sources and identify the transformations of energy observed in everyday life.
Core concepts	Suggested Activity
4.1a  The Sun is the major source of energy for Earth.  Other sources of energy include nuclear and geothermal.
4.1b  Fossil fuels contain stored solar energy and are considered nonrenewable resources.  They are a major source of energy in the United States.  Solar energy, wind, moving water, and biomass are some examples of renewable energy resources.
4.1c  Most activities in everyday life involve one form of energy being transformed into another.  For example, chemical energy in gasoline is transformed into mechanical energy in an automobile engine.  Energy in the form of heat is almost always one of the products of energy transformations.
4.1d  Different forms of energy include heat, light, electrical, mechanical, sound, nuclear, and chemical.  Energy is transformed in many ways.
4.1e  Energy can be considered to be either kinetic energy, which is the energy of motion, or potential energy, which depends on relative position.
4.2  Observe and describe heating and cooling events.
Core concepts	Suggested Activity
4.2a  Heat moves in predictable ways, flowing from warmer objects to cooler ones, until both reach the same temperature.
4.2b  Heat can be transferred through matter by the collision of atoms and/or molecules (conduction) or through space (radiation).  In a liquid or gas, currents will facilitate the transfer of heat (convection).
4.2c  During a phase change, heat energy is absorbed or released.  Energy is absorbed when a solid changes to a liquid or when a liquid changes to a gas.  Energy is released when a gas changes to a liquid or when a liquid changes to a solid.
4.2d  Most substances expand when heated and contract when cooled.  Water is an exception, expanding when changing to ice.
4.2e  Temperature affects the solubility of some substances in water.
4.3  Observe and describe energy changes as related to chemical reactions.
Core concepts	Suggested Activity
4.3a  In chemical reactions, energy is transferred into or out of a system.  Light, electricity, or mechanical motion may be involved in such transfers, in addition to heat.
4.4  Observe and describe the properties of sound, light, magnetism, and electricity.
Core concepts	Suggested Activity
4.4a  Different forms of electromagnetic energy have different wavelengths.  Some examples of electromagnetic energy are microwaves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays.
4.4b  Light passes through some materials, sometimes refracting in the process.  Materials absorb and reflect light, and may transmit light.  To see an object, light from that object, emitted or reflected from it, must enter the eye.
4.4c  Vibration in materials set up wave-like disturbances that spread away from the source. Sound waves are an example.  Vibrational waves move at different speeds in different materials.  Sound cannot travel in a vacuum.
4.4d  Electrical energy can be produced from a variety of energy sources, and can be transformed into almost any other form of energy.
4.4e  Electrical circuits provide a means of transferring electrical energy.
4.4f  Without touching them, material that has been electrically charged attracts uncharged material, and may either attract or repel other charged material.
4.4g  Without direct contact, a magnet attracts certain materials and either attracts or repels other magnets.  The attractive force of a magnet is greatest at its poles.
4.5  Describe situations that support the principle of conservation of energy.
Core concepts	Suggested Activity
4.5a  Energy cannot be created or destroyed, but only changed from one form into another.
4.5b  Energy can change from one form to another, although in the process some energy is always converted to heat.  Some systems transform energy with less loss of heat than others.