Title:

Nuclear Physics – What Keeps the Nucleus of an Atom Together? TS 654 Project 1 S. Ueland

Description:

The nucleus of an atom is made-up of electrically positive charged particles (protons) which should be pushed apart from each other, the nucleus should not exist! What holds the nucleus together? This Web Quest is to allow you to learn about what keeps the nucleus of an atom from flying apart.

During today’s class, you will access a resource through the Internet and as you get information from the internet, you will take notes and use this information to complete the assignment.

Tonight for homework, you will complete the assignment to demonstrate your newly acquired knowledge.

Tasks:

Go to the web site http://www.sciencejoywagon.com/physicszone/lessonch/12nuclear/intronuc.htm . The login is sled and the password is dog. This will start you on a 39 page quest – Use the arrow on the bottom right of each page to go on. View and read pages through to the 39^th page which starts out “This is called the “binding energy”.” Be sure your notes include the mass on a proton and a neutron and the example calculation of energy. Once you are done viewing and taking note return to this page and complete the assignment. Go to the Assignment

Assignment:

Explain what “mass defect” is. Explain why there is a mass defect. Physicist Otto Hans’ and Fritz Strassman discovered that a neutron strikes the nucleus of an U235 atom, a nuclear fission reaction occurs. When it does the neutron + the U235 results in Kr92 + Ba141 + 3 neutrons. Compare the total starting mass with the resulting final mass and calculate how much energy is released. Make sure you organize your calculations in an orderly manner and show all formulas used.

For Further Information and Self Study:

http://www.chem.ox.ac.uk/vrchemistry/Conservation/page21.htm pages 23-30

Conclusion:

Mass and energy are conserved at all levels in the universe.

The fundamental source of all energy in the universe is the conversion of mass into energy.