3/27 - Lab on Radioactive decay and progress reports

Today you got all of your work back from the third quarter. At this point, third quarter is over, and 4th quarter has officially begun. I also handed out progress reports, these are the grades that you earned during the third quarter.

Then we worked on a radioactivity and half-life lab. If you did not get a chance to turn it in, then it is due tomorrow. I'm writing out the last three questions in case you didn't have a chance to write them down yourself.

2. If a rock with 580 g of radioactive material currently has 18.125 g of parent element (original radioactive material) present. How old is the rock if the half life of the radioactive material is 2.5 million years?

3. Suppose you were given $1,000,000. How long would it take you to have less than $5 left if you spent half of it every day?

4. Suppose a material emits 25 rem/year (which would cause radioation sickness) and has a half life of 5 years. How many years before it emits only 200 millirem/year (which is safe - this is the amount of background radiation that you receive every year)?
Hint 1 : Look over the problems that we solved in class (you may use the chart you created to figure this out)
Hint 2: 1 rem = 1000 millirem

REMEMBER!!! The vocab for Chapter 17 and the erosion vocab (14 words that I gave you on Thursday - they are on Thursday page) are due TOMORROW!!!!!