Let's begin with a small number

Decroissance radioactive simulation dating

We call this rate the isotope's half-life. Let's begin with a small number.

We know that radioactive substances disintegrate at a known rate, however. Also consider permanently sealing each set in its plastic bag, if you have such a device. You may group them in any size, but working in pairs is optimal for this exercise. Strontium is chemically similar to calcium.

They need only know that such calculations are possible. After students have completed the activity, discuss the answers to the analysis questions with the whole class. The pre- and post-test quizzes, ready to hand out optional A scaled time-line for the solar system around the classroom, if possible see our Time Machine lesson. Students should complete the Analysis section of the lab sheet, which will be used as part of their assessment. Write about how the strontium might accumulate in your body teeth and bones and how it might affect you.

The mathematics of inferring backwards from measurements to age is not appropriate for most students. Students relate half-lives of radioisotopes to the application of dating rocks. Have students look at the Glossary of Nuclear Science Terms for alpha and beta decay.

Ask students to explain the terms in their own words. Context This is the second lesson in a three-lesson series about isotopes, radioactive decay, and the nucleus.

This method of measuring a rate won't work for radioactive decay. At the end of the lab, give them the opportunity to revisit these questions and change or justify their answers. List Rutherford's major achievements. This lesson can be done in two, minute class periods.

This method of measuring a

Advise students to read through the simulation first so that they understand what they should do. It is the length of time required for the disintegration of one-half of a given number of nuclei of a radioactive element. Benchmarks for Science Literacy, p. Consider using other items to replace the beans and popcorn. If they haven't changed their answers, ask them to explain why.

At the end of the

In your planning, be sure to include time at the end of the lesson for students to post their data and share the class data. Consider taking your students on a simulated journey back in time in our Time Machine. 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. Radioactive decay, also known as radioactivity, is the spontaneous emission of radiation from the unstable nucleus of an atom. Suppose we have nuclei of a radioactive isotope.

This is especially helpful in explaining how isochrones work, and why they are so compelling. See the Time Machine lesson for specifics. Have students write their answers to these questions in their science journals. The Photograhic Periodic Table of the Elements can be used to find all the known isotopes of all the elements, their decay modes, and half-lives.