Rubidium-87 Decays by Beta Decay with a Half-Life of 4

question 54

Multiple Choice

Rubidium-87 decays by beta decay with a half-life of 4.9 × 10¹⁰ yr.How many ⁸⁷Rb atoms are in a moon rock sample that has a rubidium decay rate of 3,500 disintegrations per hour?

• A)9.0 × 10¹⁶ atoms
• B)4.3 × 10^-4 atoms
• C)2.2 × 10¹⁸ atoms
• D)2.5 × 10¹⁴ atoms
• E)1.7 × 10¹⁴ atoms

---

Definitions:

Opportunity Cost

Opportunity cost represents the benefit that is missed or given up when choosing one option over another, an important concept in decision-making.

Tactical Decision

Short-term choices made by an organization, often in response to immediate challenges, that are aimed at implementing strategies effectively.

Qualitative Factors

Non-numerical elements that influence business decisions, like brand reputation or customer satisfaction.

Outsourcing Decision

The choice made by a business to contract out certain tasks or services to external providers rather than performing them internally.