Read
the instructions
that follow below and begin your investigation of atomic radiation by
identifying the components of a radioactive atom and its functions.
Answer the questions, according to your instructors directions, to
demonstrate your understanding of atomic radiation.
You are about to begin an Envirohealth WebQuest. Instructions will appear in red and questions to be answered in black. Read the directions carefully before going to any sites. Look at the questions that are to be answered from the information at a site and use the questions as objectives to direct your reading and examination of any pages. Toggle back and forth between the specified sites and these pages. Your instructor will explain to you how they wish your data displayed for grading.Let's begin! Click the green heading above each section of questions below. It will take you to your destination.
Atomic radiation has been a feature of our planet since the earth's inception. The identification and explanation of radioactive elements, however, first occurred in 1896, when Henri Becquerel discovered that uranium emitted radiation.No material has affected civilization as dramatically as nuclear radiation. The history of radiation is a checkered chronicle that ranges from the devastation of nuclear weapons to the medical benefits of radiation therapy. Nuclear radiation is clearly a "double-edged sword" that can be a destroyer of worlds on the one hand, or the purveyor of energy that may determine our future.There is much we need to learn about the substances that display this inherent duality.
Let us start our WebQuest by investigating the Visionlearning's Library presentation on Nuclear Chemistry. When you arrive there, read Nuclear Chemistry: An Introduction. The headings over each of the questions below will indicate in which section of the page the information is found to answer the questions. There are questions below that will guide you through the information and help you understand the technical details that explain atomic radiation. Enjoy the trip!
Nuclear Chemistry: An Introduction
1. Marie Curie was the first woman to win two Nobel prizes, the second of which was for discovering the radioactive elements radium and polonium.
Radiation and Nuclear Reactions
2. In 1902, Frederick Soddy proposed the theory that 'radioactivity is the result of a natural change of an isotope of one element into
3. Nuclear reactions involve changes in particles in an atom's nucleus and thus can 'decay' into lighter elements. Unlike normal chemical reactions that form molecules, nuclear reactions
4. There are three common types of radiation and nuclear changes. The first is Alpha radiation which is:
5. There are three common types of radiation and nuclear changes. The second is Beta radiation which is:
6. There are three common types of radiation and nuclear changes. The third is Gamma radiation. Common examples of Gamma radiation are:
7. Radioactive decay proceeds according to a principal called the half-life. The half-life is the amount of time necessary for half of the radioactive material to decay.
8. The decay reaction and half-life of a substance are specific to the isotope of the element undergoing radioactive decay according to the chart on the right.
9. Radium has a half-life of 3.823 days according to the chart on the right.
Now let's move for a moment away from the natural radiation of nuclear decay to simulated nuclear reactions. The animation you are about to see shows nuclear fission when a nutron is absorbed by a Uranium 235 nucleus. Click on Animation of Nuclear Fission. When you arrive there, watch the animation and read the accompanying text. There are questions below that will test your understanding of what you have seen.
10. The U235 nucleus absorbs a neutron and the nucleus fissions (splits) releasing more neutrons and two new nuclei. One of the new nuclei is that of krypton.
11. As increasing numbers of unstable atoms experience fission, more energy and neutrons are released, resulting in:
A nuclear chain reaction is modelled in the video linked below. The chain reaction model runs via a lattice of mouse traps each able to release two "neutrons". The traps, are set up next to a wall to maximize the possibility of any neutrons rebounding and initiating more neutron releases. Click on the link below and wait for the video to download. Run the video and see what is an excellent model of an uncontrolled chain reaction.
Mouse Trap Video You should now have a fairly good grasp of radiation and its implications for generating energy. As the unstable nuclei of atoms decay they act as "nuclear clocks". They release their particles in a regular fashion that can be measured. These measurements can be used to estimate how long these atoms have been present in the rocks, or fossils, in which they are found. This method of measuring time is a valuable tool to geologists, anthropologists and paleontologists as they attempt to place their discoveries in some chronological order.
Let's do a lab that relates to dating rocks and fossils to conclude this exercise! Click on the link below and go to the page containing the lab's instructions and data chart. You can fill out the data chart online. When you have finished the lab and graph, print the page and follow your teacher's instructions. Your instructor will supply the materials and you supply the brain-power. Enjoy this "edible" investigation.
Half-Life Simulation