Short Answer
¹⁴C is produced in the atmosphere by cosmic ray interaction with ¹⁴N and has a half-life of ~5730 years is the best answer.
Nuclear and particle questions tend to hinge on conservation laws, decay rules, interaction types, or scale. A clean answer usually comes from identifying the process before the details.
Atmospheric ¹⁴C maintains a near-constant ratio with ¹²C; once organisms die, ¹⁴C decays at t₁/₂ ≈ 5730 years, allowing dating.
Why This Answer Is Correct
This is a Medium-level question in Nuclear & Particle Physics. The prompt is really testing whether you can connect the concept to its defining physical relationship instead of picking a nearby-but-wrong term.
Track conserved quantities carefully: energy, momentum, charge, lepton number, baryon number, and spin-like constraints when relevant.
Choices At A Glance
- A. It is stable
- B. ¹⁴C is produced in the atmosphere by cosmic ray interaction with ¹⁴N and has a half-life of ~5730 years
- C. It decays in microseconds
- D. It emits X-rays
When similar options appear on an exam, eliminate the ones that break the core law, use the wrong units, or confuse a definition with a consequence.
Study Next
Review the related formula library
review the theoretical physics hub
Topic Snapshot
Topic: Nuclear & Particle Physics
Difficulty: Medium
Best next move: Re-state the governing law in your own words, then solve one more example from the same topic before moving on.