If you ment to say "What CANNOT be created or destroyed but can be changed from one to another" than you are looking for matter and energy. Energy cannot be created or destroyed, it can only change form. for example, the sun shines light on to a corn plant, which powers photosynthesis. this is a transfer from radiation energy to chemical energy, stored in the cells of the corn. when you eat this corn, and use that energy to jump up and down, that is a transfer of chemical energy to kinetic energy.
Mass can also (at least in theory) be converted into energy in accordence with E=Mc2 with E=energy, M=mass, and c=the speed of light
Changed from one form to another - energy cannot be created or destroyed it can only be changed from one form to another.
It is a fundamental that energy can neither be created or destroyed just changed from one form to another.
Energy cannot be created or destroyed but merely changed from one form to another.
Matter can be neither created nor destroyed but only changed from one form to another.
Energy cant be created or destroyed . The total energy in the universe is constant.The energy can be changed into one energy to another .
Changed from one form to another - energy cannot be created or destroyed it can only be changed from one form to another.
Mass is equivalent to energy. Neither can be destroyed or created, only changed from one form to another.
It is a fundamental that energy can neither be created or destroyed just changed from one form to another.
Energy cannot be created or destroyed but merely changed from one form to another.
The Law of the Conservation of Energy. Stating it can be neither created or destroyed but changed from one form to another.
Energy cannot be created or destroyed. The energy just changed from one form to another for of energy.
One of most basic laws of science is the Law of the Conservation of Energy. It states that energy cannot be created or destroyed; it can only be changed from one form to another.
Conservation of matter means, matter can neither be created nor be destroyed but it can be changed from one form to another.
Matter can be neither created nor destroyed but only changed from one form to another.
Matter can not be created nor destroyed during any process, so no matter can not be destroyed during a chemical change.
The statement "Matter can neither be created nor destroyed but can be changed in form" is the substance of the law of conservation of matter.
Conservation of matter means, matter can neither be created nor be destroyed but it can be changed from one form to another.