• QUESTIONS BEFORE LECTURE 23

now think about these

• How much energy is in a gram of mass? Express it in megawatt years.
• What fraction of mass energy is released in chemical processes, such as in our body?
• What fraction of mass energy is released in nuclear processes, such as in the sun?
• What is a nucleon?
• Pronounce correctly nucleus, nuclei, nucleon, nuclear.
• What is a big difference between positive and negative energy? Which familiar kinds of energy are positive and negative?
• Define binding energy. What is the most tightly bound nucleus?
• Why do nuclei want to move up the binding energy curve? Where do they stop?
• Name two elements which can undergo nuclear fusion and one which can undergo nuclear fission.
• Name two processes driven by fusion and two by fission.
• What is the significance of the lower energy well for the daughters than for the parents?
• What is the energy hill about?
• What types of energy are released in fusion and fission?
• What is the meaning of critical mass? chain reaction? control rod?
• What is the significance of E = mc²?