Which of the following is NOT a true statement regarding radioactive isotopes?

• A. Radioactive decay can emit alpha, beta, or gamma radiation.
• B. Radioactive isotopes can be used in medical imaging and treatment.
• C. Radioactive isotopes spontaneously decay to form more stable nuclei.
• D. All radioactive isotopes have the same half-life.

Answer: (D)

Verified step by step guidance

1. Understand the concept of radioactive isotopes: these are unstable nuclei that undergo radioactive decay to achieve a more stable state.
2. Review the types of radiation emitted during radioactive decay: alpha particles (helium nuclei), beta particles (electrons or positrons), and gamma rays (high-energy photons). All these types can be emitted depending on the isotope.
3. Recognize the applications of radioactive isotopes, such as their use in medical imaging (e.g., PET scans) and treatment (e.g., radiation therapy), which is a true statement.
4. Recall that radioactive isotopes spontaneously decay over time, transforming into more stable nuclei, which is a fundamental property of radioactivity.
5. Identify that the statement 'All radioactive isotopes have the same half-life' is false because each radioactive isotope has a unique half-life, which is the time required for half of the sample to decay.