Energy: Forms, Sources, and the Law of Conservation

Energy and Its Different Types

Thermal Energy or Heat

Thermal energy, or heat, is related to a body's temperature. Heat is a form of energy transferred from one body to another.

Mechanical Energy

Mechanical energy is the energy that drives motion in everything, such as cars and wind. It is the sum of potential and kinetic energy.

Chemical Energy

Chemical energy is the energy associated with chemical reactions.

Nuclear Energy

Nuclear energy is obtained by inducing changes in an atom's nucleus through nuclear fission or nuclear fusion.

Electromagnetic Energy

Electromagnetic energy is associated with electromagnetic waves. It is responsible for many phenomena, including radio and television waves, microwaves, and X-rays.

Energy in Living Things

Organisms transform what we eat into water, energy, and carbon dioxide, using the oxygen we breathe. Our body converts this into mechanical energy, thermal energy (heat), and electrical energy (transmission of nerve impulses).

Law of Conservation of Energy and Matter

The law of conservation of energy, established by J.R. von Mayer in 1845, states that energy is neither created nor destroyed, only transformed.

Energy Sources

Energy sources are those that can generate energy as heat, light, etc. They are divided into renewable or inexhaustible and non-renewable.

Renewable Energy

Solar Energy

Solar energy reaches the Earth from the Sun in the form of radiation. There are two main processes for harnessing it:

• Direct conversion into electricity using photovoltaic or solar cells.
• Conversion with solar thermal devices that heat a fluid for use.

Advantages: It is an inexhaustible, free, and clean energy source with a low environmental impact.

Disadvantages: Its use is limited in places without continuous sunlight, and specialized facilities are required.

Biomass Energy

Biomass refers to the organic matter in living things. It is produced from plant products and their derivatives.

Advantages: It is a renewable energy source, promotes recycling, reduces organic waste, and has positive CO2 emissions.

Drawbacks: It requires large cultivation areas and has a high production cost.

Nuclear Energy

Fission

Fission is the process of breaking up a heavy nucleus when it collides with a neutron. This produces two lighter nuclei and neutrons, which in turn collide with other nuclei.

Fusion

Fusion is the process of combining light nuclei, like hydrogen (H), to form larger, more stable nuclei, like helium (He). The energy from the Sun and stars is due to nuclear fusion.

Nuclear Energy in Power Plants

Nuclear energy is used to generate electricity in nuclear power plants. It is not considered a renewable energy source because deposits of these elements can be scarce.

Advantages: Large amounts of energy can be obtained from a small amount of fuel.

Disadvantages: It is a non-renewable energy source with a significant environmental impact due to tons of radioactive waste with half-lives spanning hundreds or thousands of years. There are also dangers associated with the transport and handling of reactive materials.