A radioactive substance decays to half its mass every 4 days. If the initial mass is 160 grams, what is its mass after 12 days?

Sat, 09 May 2026 19:07:40 +0000

**Why Awareness of Radioactive Decay Is Growing in the US—And What It Means for You**
Daily, quietly shaping science, energy, and industry, radioactive decay captures quiet focus. Ever heard that a substance can lose half its mass every few days? Today, people are tuning in because real-world applications of this natural process are influencing medicine, nuclear power, and environmental monitoring. One widely discussed example involves a material that halves its mass every 4 days—starting from 160 grams. How much remains after 12 days? This question reflects growing interest in predictable decay patterns that serve both technical and safety-critical roles. Whether tracking radioactive isotopes in research or understanding contamination timelines, knowledge around this cycle builds clarity in a complex field. **Why This Decay Pattern Is Trending Now**
Modern conversations about radioactive decay reflect a rising awareness across tech, health, and energy sectors. From medical imaging with short-lived isotopes to nuclear waste management, understanding half-life decays lays the groundwork for safe handling. In the US, increasing integration of nuclear technologies—paired with greater public fact-checking via mobile devices—drives demand for clear, non-sensational explanations. The simplicity of “half-life every 4 days” makes this topic both accessible and universally engaging, sparking curiosity about natural processes that influence daily life more than most realize. **How Half-Life Decay Actually Works: Explained Clearly**
A half-life is the time taken for a radioactive substance to reduce its mass by half. In this case, every 4 days, the material decays exponentially: starting at 160 grams, it loses half—80 grams—after 4 days. The process repeats: 80 grams become 40 grams after another 4 days (8 total), and finally 20 grams remain at 12 days. This decay follows a precise mathematical pattern rooted in quantum physics, making it predictable and reliable. The key is consistent decay rate: it doesn’t degrade linearly; each stage cuts mass by half, accelerating decay over time. Understanding this mechanism reveals why the 4-day interval defines measurable change across practical timelines. **Common Questions About Decay Over 12 Days**
*H3: How long does the 160-gram sample stay at 80 grams?*
After 4 days: 80 grams remain.
*H3: What about the next stage?*
Yes, after 8 days, half of 80 grams—the 40 grams—decay, leaving 40 grams.
*H3: Why not a linear drop-off?*
Because radioactive decay is exponential: each half-life cuts the remaining mass, not a fixed amount.
*H3: Is the decay constant or variable?*
The process remains constant under normal conditions, with decay rates determined by isotopic stability, unaffected by temperature or pressure.