Radioactivity: a Sphere Made of a Radioactive Isotope Initially Has

question 79

Multiple Choice

Radioactivity: A sphere made of a radioactive isotope initially has a mass of 6.88 kg. The half-life of this isotope is 1.34 h, and it decays by β^- emission. At the end of 2.68 h, what is the mass of this sphere?

• A) 6.88 kg
• B) 3.44 kg
• C) 1.72 kg
• D) 2.53 kg

---

Definitions:

Cellphones

Portable electronic devices used for communication, including voice calls, text messaging, and accessing the internet.

Sociologists

Scholars and professionals who study the development, structure, and functioning of human society and social problems.

Power Structures

Refers to the organization and distribution of power within societies, institutions, or organizations, which shapes interactions and outcomes.

Progressive Social Change

An approach to social development that aims to make gradual improvements in society through reforms and innovations.