1. An atom has a tremendous amount of energy locked in _____________ its , and it can be released by firing particles (sometimes called " atomic bullets") into it at high speeds.
2. Albert ____________ said that energy is equal to the mass times the speed of light squared.
3.The term _______________ means the splitting of atoms (breaking up the nucleus).This may result in a chain reaction, as particles released split other nuclei, and these in turn split others, and
so on.
4. The smallest amount of an element needed to produce a chain reaction is call its
"critical _____________ ."
5.A nuclear ______________ is used to produce heat from a nuclear fuel by controlling the chain reaction of the fission.
6. Nuclear _____________ is the opposite of fission. In this process, two or more atomic nuclei unite.
7. For nuclear fusion to occur, extremely ___________ temperatures are required.
8. Nuclear fusion occurs in the ________ and other stars, but only a small fraction of the total energy released reaches the earth.
9. Since very large amounts of energy can be produced from very small amounts of nuclear fuel, this may solve the problem of energy shortages--provided scientists can find a way to dispose of nuclear _____________ safely and prevent pollution.
10. In the space below, explain in your own words what you think Einstein meant by the remark he once made to an interviewer. He said world war lV would be fought with sticks and stones.
11. ______ elements give off radiation from their nuclei and change into other elements over a period of time.
12. _______are the tiny bundles of energy emitted by a X-ray tube.
13. Certain substances absorb X-rays more readily than others. _______ , for example, absorb more than flesh, which is why X-rays are useful to doctors.
14. Large doses of radiation at one time or small doses over a long period of time are _______ to the human body and can cause death.
15. A radioacitve element discovered by Pierre and Marie Curie is ________.
16. Radioactive istopoes, such as cobalt 60, are used in treating _______ (disease). They are also used as tracers in the bloodstream to locate blockages, tumors. and so on.
17. X-ray technicians wear aprons coated with _______, which protect their bodies by absorbing the X-rays.
18. _______ materials, such as certain types of minerals, glow when exposed to radiation.
19. The three types of rays emitted by radioactive elements are ________________________________ none of which can be seen or detected without the use of scientific intruments.
20. When there are more _______ than protons in the nucleus of an atom, the element (or its isotope) is likely to be unstable (radioactive).
21. Look up the names of William Roentgen and A.H. Becquerel on the internet or other reference books. In the space below, write a sentence about each of these men, indicating what they contributed to the study of radiation.