The law of conservation of energy states that energy can not be created (made from nothing), or destroyed and that energy can be changed from one form to another (such as electrical energy in to heat energy).

 *to be continued*

 I. Every object in a state of uniform motion (constant velocity) or at rest tends to remain in that state of motion unless an external force is applied to it.

Nuclear Fission (Nuclear Fission)

Uranium – 235
Plutonium – 239

Neutron strikes U-235 or P-239 which causes them to split and release more neutrons that strike more U-235 and P-239 and starts a chain reaction.