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Module 8

1. Module 8

1.20. Lesson 4

Lesson 4

Module 8—Nuclear Decay, Energy, and the Standard Model of the Atom

 

Lesson 4—The Subatomic World

 

Get Focused

 

A photograph shows a technician on a bicycle beside the Large Hadron Collider, which is nearly 27 km long, buried 100 m below the border of Switzerland and France. The collider is a tube approximately one metre in diameter, running through a concrete-lined tunnel that curves gradually to the left as it disappears into the background.

© CERN 2008. Used with permission.

The Large Hadron Collider is the world’s most powerful machine. It is 27 km long and is buried 100 m below the border of Switzerland and France.

Sometimes you have to think big to find something really small. Deep underground, underlying the border between Switzerland and France, is a gigantic scientific instrument. The Large Hadron Collider (LHC) is the biggest machine in the world. It is nearly 27 km in circumference and contains 9300 magnets along a circular path. When it operates at full power, trillions of protons travel its circumference 11 245 times every second—nearly the speed of light!

 

Coming in the opposite direction and at the same speed, a second group of protons collide with them. All told, 600 million collisions should occur every second, with energies that will produce temperatures 100 000 times that of the Sun’s core. If it sounds impressive, that’s because it is! With these energies, never before seen on Earth, the protons will break apart, revealing the subatomic world that makes them up. The products of such a high-energy collision should help scientists answer some unresolved questions about the subatomic world, such as the following:

  • What is the origin of mass? What makes up the mass in a nucleon?
  • What makes up 96% of the universe? What is dark matter?
  • Where is antimatter, as predicted by the standard model of the atom?
  • What happened in the first few seconds of the universe?
  • Are there other dimensions in the space-time continuum?

These are big, heavy questions. They will require massive amounts of energy to study. The LHC was built to provide enough energy to try to answer questions like these and to fill in the knowledge gaps that still exist in our understanding of the universe beyond our planet and reveal the fundamental make-up of the subatomic universe. These questions are beyond the scope of this course but show that, despite claims that humans understand the universe, there are still many basic concepts that we cannot explain.

 

Watch and Listen

 

Take a look at how the LHC will use hydrogen gas to investigate the quarks and particles from the inside of a proton in the video called “The Bottle to Bang.”

 

In Lesson 4 you will learn about ongoing developments that are informing our models of the structure of matter.

 

In this lesson you will focus on answering the following essential questions:

  • 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?
Module 8: Lesson 4 Assignment

 

Your teacher-marked Module 8: Lesson 4 Assignment requires you to submit responses to the following:

  • Assignment—A 1, A 2, A 3, A 4, and A 5
  • Reflect and Connect—RC 1, RC 2, RC 3, and RC 4

After a discussion with your teacher, you must decide what to do with the questions that are not part of your assignment. For example, you may decide to submit to your teacher the responses to Try This questions that are not marked. You should record the answers to all questions in this lesson and place those answers in your course folder.