To do this lesson and understand half-life and rates of radioactive decay, students should understand ratios and the multiplication of fractions, and be somewhat comfortable with probability.
Games with manipulative or computer simulations should help them in getting the idea of how a constant proportional rate of decay is consistent with declining measures that only gradually approach zero.
All living things on Earth are made up of a high percentage of an element called carbon.
Carbon combines with other elements in complex ways to form the molecules that make up our bodies.
Alpha particles emitted by the americium ionize the air, making the air conductive.
Any smoke particles that enter the unit reduce the current and set off an alarm.
This document describes a few of the more commonly encountered and familiar consumer products that can contain sufficient radioactive material for it to be distinguished from background with a simple handheld radiation survey meter.
Most residential smoke detectors contain a low-activity americium-241 source.
Although they might be familiar with the use of radiation to diagnose disease and treat cancer, many people, when they hear the terms "radioactive" and "radiation," tend to think of mushroom clouds and the monster mutants that inhabit the world of science fiction movies and comic books.
Careful analyses can identify and quantify the radioactive material in just about anything.
Most carbon on Earth is not radioactive, but a very small percentage is.
Thus, as living things take in carbon, they inevitably will take up a small amount of radioactive carbon into their bodies.
(Radioactive nuclei will be those candies with the marked side down.) 2.