Radioactivity and particles：練習問題

A radioactive sample has an initial activity of \( 1600 \text{ Bq} \). If the half-life of the isotope is \( 8 \text{ days} \), what will the activity be after \( 24 \text{ days} \)?

In the context of a nuclear fission reactor, which statement correctly explains the function of the moderator and the control rods?

A nucleus of carbon-14, \( _{6}^{14}C \), undergoes radioactive decay to form a nucleus of nitrogen-14, \( _{7}^{14}N \). Which type of radiation is emitted during this process?

When comparing the ionising and penetrating powers of alpha (\( \alpha \)) and gamma (\( \gamma \)) radiation, which statement is correct?

A specific nuclear fission reaction is represented by the equation:
\( _{92}^{235}U + _{0}^{1}n \rightarrow _{54}^{140}Xe + _{38}^{94}Sr + X \times _{0}^{1}n \)
What is the value of \( X \), the number of neutrons released?

Compare alpha (\(\alpha\)) and gamma (\(\gamma\)) radiation in terms of their ionizing power and their penetrating ability through materials.

Define nuclear fusion and explain why this process requires extremely high temperatures and pressures to occur in stars.

A radioactive source has an activity of \(800\) Bq. If the half-life of the isotope is \(6\) hours, calculate the activity of the source after \(24\) hours have passed.

Nuclear power stations use the process of nuclear fission to generate electricity.

(a) Describe what happens when a nucleus of Uranium-235 undergoes fission.
(b) In a nuclear reactor, the reaction must be controlled to maintain a steady rate. Explain the roles of the moderator and the control rods in achieving this.
(c) State the main difference between nuclear fission and nuclear fusion.