Module 8
1. Module 8
1.24. Page 5
Module 8—Nuclear Decay, Energy, and the Standard Model of the Atom
Lesson Summary
- How is it possible to probe the subatomic world?
- What subatomic particles make up the proton and neutron?
- How does the discovery of antimatter and subatomic particles inform the latest models concerning the structure of matter?
In this lesson you learned that particle tracks can be interpreted to identify the charge-to-mass ratio and type of charge on subatomic particles. By colliding particles, such as protons, at extremely high energies, the contents of these particles can be probed and studied. Current particle accelerators are among the most powerful machines ever built and are capable of causing particle collisions at energies never before seen on Earth.
Based on particle track research and theory, the subatomic world is composed of strange ideas and particles such as antimatter, mediating particles, and the quarks that make up protons and neutrons. Some evidence for up and down quarks is provided by beta decay and beta-positive decay, which is caused by the electroweak force.
Beta Decay
Beta Positive Decay
Current theory that relates the mediating particles to the fundamental forces of electroweak and strong nuclear force are contained in the Standard Model, which is evolving as more experimental evidence gathers. In subatomic research, theory and observation interact, one leading to the other and vice versa. Together, both theoretical and experimental physicists are working toward a grand unified theory, or theory of everything, that will bring connection to all the fundamental forces of the universe and the particles that mediate, create, and sustain them.
Lesson Glossary
antimatter: an extension of the concept of normal matter that is made up of particles where antimatter is made up of antiparticles
All particles have an antiparticle.
bubble chamber: a device that tracks particles using bubbles in liquefied gas
CERN: Conseil Européen pour la Recherche Nucléaire (world’s largest particle physics laboratory)
CERN had the first web server and posted the first page on the World Wide Web. See CERN’s website to see that historic first page.
cloud chamber: a device that tracks particles using condensed gas vapours
fundamental particle: a particle that cannot be divided into smaller particles; an elementary particle
gluon: a mediating particle for the strong nuclear force
graviton: a hypothetical mediating particle for the gravitational force
mediating particle: a virtual particle that carries a fundamental force
quark: a fundamental particle in the hadron family
standard model: the current theory describing the nature of matter and the fundamental forces
virtual particle: a particle that exists for such a short time that it cannot be detected
