Composite Particle
Composite Particles
A composite particle is a particle that is composed of two or more elementary particles. Unlike elementary particles, which are not known to be made up of smaller constituents, composite particles have a measurable internal structure. They play a crucial role in the Standard Model of particle physics, which classifies subatomic particles into various categories.
Types of Composite Particles
Hadrons
Hadrons are composite particles made of quarks held together by the strong force. There are two main types of hadrons:
- Baryons: These particles are composed of three quarks. The most well-known baryons are the proton and the neutron, which make up atomic nuclei.
- Mesons: These particles are composed of one quark and one antiquark. Mesons are often involved in mediating the strong force between baryons.
Atomic Nuclei
Atomic nuclei are another form of composite particle, composed of protons and neutrons, which are themselves baryons. The nucleus is held together by the nuclear force, a residual effect of the strong interaction between quarks.
Applications and Phenomena
Thermoelectric Effect and Composite Particles
The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. This effect can be observed in composite materials where the internal structure of the composite particles plays a significant role in the efficiency of energy conversion. For instance, thermoelectric materials often contain composite particles designed to optimize the Seebeck effect, a key phenomenon in thermoelectric generators.
Atomic Batteries and Composite Particles
Atomic batteries, also known as nuclear batteries, utilize the decay of radioactive isotopes to generate electricity. These batteries often incorporate composite particles to enhance their efficiency and safety. For example, the radioisotope thermoelectric generator (RTG) employs composite materials to convert heat released by radioactive decay into electrical energy using the thermoelectric effect.
Notable Examples of Composite Particles
- Proton: Consists of two up quarks and one down quark.
- Neutron: Consists of two down quarks and one up quark.
- Pions: A type of meson composed of an up or down quark and their corresponding antiquarks.
- Deuterium nucleus: A simple atomic nucleus consisting of one proton and one neutron.