Matter and Energy

Matter is the stuff that makes up our universe.  It is defined as any substance that occupies space and has mass.  This means that it has a volume and, on earth, it can be weighed.  Matter is usually made of atoms, which are the building blocks of matter, unless it is smaller than atoms.  Particles like protons, neutrons, and electrons (which are the building blocks of atoms), or even smaller particles like hadrons and quarks are considered matter as well.  Matter comes in several states: solids, liquids, gases, and plasma. The state that matter is in at any point in time can be determined by the amount of energy interacting with the matter.  According to the Law of Conservation of Matter, matter can not be created or destroyed, but can only be changed.  It takes energy to change matter.

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Energy refers to just about everything else in the universe that is not matter.  Energy is required to make matter move, and we can measure that amount of energy.  Energy doesn't have mass, and it does not take up any space.  Energy always connects somehow to the motion of matter.  Kinetic energy is the energy that matter has that allows it to move.  Potential energy is stored energy that will be converted into kinetic energy.  This means that the energy will allow matter to move later, just not right now.  Thermal energy has to do with the speed at which the atoms and molecules that make up matter are moving. Electrical energy has to do with the movement of electrons through matter.  Nuclear energy involves the movement of subatomic particles as the nuclei of atoms are torn apart or joined together.  Light energy involves the movement of particles called photons as they travel in waves.  Light is the only form of energy visible to the human eye.  According to the Law of Conservation of Energy, energy cannot be created or destroyed, only changed from one form to another.

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It is the connection between energy and matter that is the heart of this crosscutting concept of Energy and Matter.  How is matter changing?  How is energy involved in that change?  How is one form of energy getting changed to another?  Everything that happens in our world is a combination of changing matter and changing energy.  By understanding how these two things work together (by analyzing Patterns and finding Cause and Effect relationships) we get a better understanding of how the universe works.