Energy

Magnetic and electrical energy are closely related to one another. When electrons move through a wire, a magnetic field is created around the wire. If the wire carrying the electrons is wound around a a metal bar of iron the iron will become magnetic and is called an electromagnet. The magnetic energy generated can be used to attract other metal parts and is used in devices like the magnetic hoists used to lift old cars into the car compactor.

Kinetic energy is the energy of motion. An object that has motion - whether it is vertical or horizontal motion - has kinetic energy. There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another). To keep matters simple, we will focus upon translational kinetic energy. The amount of translational kinetic energy (from here on, the phrase kinetic energy will refer to translational kinetic energy) that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object.

The heat energy of a substance is determined by how active its atoms and molecules are. A hotobject is one whose atoms and molecules are excited and show rapid movement. A cooler object's molecules and atoms will be less excited and show less movement. When these guys are in the excited state, they take up a lot of space because they're moving around so fast. When the atoms and molecules settle down, or cool down, they take up less space.

Light energy is carried as an electromagnetic radiation, what we call visible light is a small part of the total spectrum. Luminous intensity is measured in candelas, which is closely related to what used to be called candle-power. The most energetic light sources are lasers, which can be made so powerful they will cut even metals. 

Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s². Since the zero of gravitational potential energy can be chosen at any point (like the choice of the zero of a coordinate system), the potential energy at a height h above that point is equal to the work which would be required to lift the object to that height with no net change in kinetic energy. Since the force required to lift it is equal to its weight, it follows that the gravitational potential energy is equal to its weight times the height to which it is lifted.

The energy held in the covalent bonds  between atoms in a molecule is called chemical energy. Every bond has a certain amount of energy. To break the bond requires energy -- in chemical language it is called endothermic. These broken bonds then join together to create new molecules, and in the process release heat -- chemists call this exothermic. If the total heat given out is more than the heat taken in then the whole reaction is called exothermic, and the chemicals get hot. The burning of methane in oxygen is an example of this. If the heat taken in is more than the heat given out then the whole reaction is endothermic and the chemicals get cold. Combining carbon and hydrogen to make methane is an example. We rarely meet such reactions in every day life. They happen in living cells, the energy being supplied by sunlight or some other source.

Sound energy is a wave of vibrations in a material. Depending on how many sound waves come in a certain period of time, the pitch of the sound that we hear moves up and down. This is called the frequency. Also, depending on the strength of the waves, the sound is louder or softer. 
Sound travels at different speeds depending on the material it is travelling through. It travels the fastest through solids because they are so dense. It travels slower through liquids and gases because they're not as dense.

Electricity is the flow of electrical power or charge. It is both a basic part of nature and one of our most widely used forms of energy.

Electricity is actually a secondary energy source, also referred to as an energy carrier. That means that we get electricity from the conversion of other sources of energy, such as coal, nuclear, or solar energy. These are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or nonrenewable.

Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched. According to Hooke's law, the force required to stretch the spring will be directly proportional to the amount of stretch.

Nuclear power is generated using Uranium, which is a metal mined in various parts of the world.

The first large-scale nuclear power station opened at Calder Hall in Cumbria, England, in 1956.

Some military ships and submarines have nuclear power plants for engines.

Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels.