▪ What is the nucleus of an atom...?

▪ What is the nucleus of an atom made of...?

▪ What does it mean if two objects are fused...?

▪ What is a fissure in a rock...?

Fission simulation:

Watch the simulation carefully.  Can you see what is happening?

Click to Run

Think about:

▪ What kind of atoms are we splitting?

▪ What particle is fired at the atom?

▪ Which part of the atom "splits?"

▪ What do you notice about the two fragments?

▪ What is "ejected" during this process?

▪ What else is released (hint: you won't be able to see this!)

Higher tier students:  Try to use these terms in your answers.

nuclei          nucleons          atomic number          parent nucleus          neutron           daughter nuclei

Nuclear fission can lead to a chain reaction, under the correct circumstances.  Watch the next tab of the simulation to see how a chain reaction occurs.

Describe the process of a chain reaction, thinking about:

▪ How can more nuclei be "fissioned", without firing additional neutrons?

▪ Why does the chain reaction sometimes not start on the first attempt?

▪ Why does the rate of fission reactions normally increase rapidly?

Nuclear fission is not the only way to release energy from atoms.  We can also use nuclear fusion reactions.  Nuclear fusion reactions involve joining light nuclei, under immense temperatures and pressures, to form heavier nuclei.  For example, hydrogen nuclei can be fused to form helium nuclei.  This particular fusion reaction is the process which powers the sun!

▪ Describe the process of hydrogen fusion.

▪ Explain why sustained fusion reactions are difficult to achieve on Earth.

▪ Write a balanced equation for the process.

MAT / Extension

Most of the atoms in your body were produced in stars.  Effectively, you are made of stardust (or nuclear waste, depending on your perspective!)

Explain how fusion reactions in stars led to the production of the heavier elements in your body.

Extension / MAT work:

A