Question

Indicate whether each of the following is characteristic of the fission or fusion process or both: a. Neutrons bombard a nucleus. b. This nuclear process occurs in the Sun. c. A large nucleus splits into smaller nuclei. d. Small nuclei combine to form larger nuclei.

Short answer

(a) Fission, (b) Fusion, (c) Fission, (d) Fusion.

Step-by-step solution

Identify Process Involving Neutron Bombardment

Understand that fission is the process where a neutron bombards a nucleus, causing it to split into smaller nuclei. Therefore, statement (a) corresponds to fission.

Identify the Process Occurring in the Sun

Recognize that fusion is the process which occurs in the Sun, where small nuclei combine to form a larger nucleus. Hence, statement (b) corresponds to fusion.

Identify the Process Where Large Nucleus Splits

Understand that fission involves a large nucleus splitting into smaller nuclei. Thus, statement (c) is characteristic of fission.

Identify the Process Where Small Nuclei Combine

Know that fusion is the process whereby small nuclei combine to form larger nuclei. Therefore, statement (d) is characteristic of fusion.

Key concepts

Fission

Fission is a type of nuclear reaction where a large, unstable nucleus splits into two or more smaller nuclei, along with the release of energy. This process is often initiated by neutron bombardment, where a neutron collides with the nucleus, causing it to break apart. Key points to remember about fission:

• Involves splitting a large nucleus.
• Triggered by neutron bombardment.
• Releases a significant amount of energy, often in the form of heat.

Fission is used in nuclear reactors and atomic bombs due to the large amounts of energy released.

Fusion

Fusion is another type of nuclear reaction but works differently from fission. Instead of splitting large nuclei, fusion combines small nuclei to form larger, more stable nuclei. This process releases energy as well but typically occurs under extremely high temperatures and pressures. Key points about fusion:

• Combines small nuclei into larger ones.
• Requires high temperatures and pressures.
• Produces a lot of energy, more than fission.

Fusion is the process that powers the Sun and other stars, making it the primary energy source in the universe.

Neutron Bombardment

Neutron bombardment is a process where neutrons are directed at a nucleus, often causing it to become unstable and split. This is a key mechanism in nuclear fission reactions. Important aspects of neutron bombardment:

• Neutrons collide with nuclei to cause reactions.
• Initiates the fission process by making the nucleus unstable.
• Often used in controlled nuclear reactions in reactors.

Understanding neutron bombardment helps in comprehending how nuclear reactors are controlled and managed.

Nuclear Processes in the Sun

The Sun's energy comes from nuclear fusion. Within its core, extreme temperatures and pressures allow hydrogen nuclei to combine and form helium, releasing enormous amounts of energy. This energy travels through space and reaches Earth as sunlight. Key points about nuclear processes in the Sun:

• Fusion of hydrogen nuclei into helium.
• Occurs under extreme conditions, millions of degrees in temperature.
• Produces energy that powers the Sun and influences life on Earth.

These fusion reactions in the Sun are continuous and provide a sustainable and long-term source of energy.