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Science 10 - Radiation Review 1. The word ______is a general, unspecific term that can refer to sever types of things. ______radiation includes visible light, X-rays, and heat. 2. ______light consists of all the colours of the rainbow (R O Y G B I V). 3. A ______is the effect of electromagnetic radiation (specifically ______light) on the skin. 4. Invisible ______can be used to make photographs to show if bones are broken. 8. Radio waves have ______wavelengths and ______frequencies. On the other end of the spectrum, X-rays and Gamma Rays have short wavelengths and high frequencies. Red light has a longer wavelength than Blue light. Except for visible light, all electromagnetic radiation is invisible. 9. The higher the frequency of the radiation, the greater its amount of ______. This is why X Rays and Gamma rays are dangerous to living things: they have enough energy to damage cells. 10. Atoms that emit radiation from their nuclei are said to be ______. When an unstable nucleus emits radiation, it is said to undergo radioactive ______. 11. There are three types of radiations that radioactive nuclei normally emit: ______radiation, ______radiation, and ______radiation. Radiation can be detected using an instrument called a ______Counter. 12. Alpha particles are like a ______nucleus. They consist of two ______and two ______. They are the heaviest but least penetrating. 13. Beta particles are like high energy ______. When a nucleus undergoes beta decay, a neutron is converted to a ______and an ______. The ______is emitted as a beta particle, but the ______remains in the nucleus. The atomic number of an atom undergoing beta decay, therefore, will always ______by one. The ______number will not change. 14. ______rays have no mass and travel at the speed of ______. They are a form of ______radiation. They are the ______penetrating. 15. The sum of the number of protons and neutrons in the nucleus is called the ______number. 16. All atoms of the same element have the same ______number, but can have different ______numbers. Atoms of the same element that have different mass numbers are called ______. 17. Carbon-13 has ______protons and ______neutrons. The "13" stands for the ______number. Carbon-14 has ______protons and ______neutrons. 18. The type of radioactive decay that does not give off a particle is called ______decay. After the nucleus has undergone this sort of decay, however, it is more ______. 19. Alpha and beta decay always results in new type of ______being formed. A new type of nucleus being formed is called a ______. 20. When a nucleus goes through alpha decay, its mass number ______by ______units. 21. The ______of a sample is the number of nuclei that undergo radioactive decay per second. It is measured in units called ______(Bq). 22. The activity of a sample of a radioactive isotope ______with time, since there are less nuclei left in the sample to decay. However, the rate of decay for any radioactive isotope is ______. 23. The time that it takes for 50% of the nuclei in a radioactive sample to decay is called ______. This time is the ______regardless of the starting amount of the radioactive isotope. For example, if you start with 96 grams of radioactive Thorium (which has a half-life of 24 days), after 24 days you would have _____ grams left, after 48 days you would have _____ grams left, after 72 days (which is equal to three half-lifes) you would have _____ grams left, and so on. 24. The total amount of radiation that strikes you from all sources outside and inside you is known as the ______radiation, and there is very little that you can do about it. 25. Alpha, beta, gamma, X-rays, and ultraviolet radiation are all very ______, as they can knock electrons off of atoms (forming charged atoms called ions). For this reason, these types of radiation are called ______radiation. 26. Ionizing radiation can cause changes in your DNA! These changes are called ______, which can cause normal cell division to go "out of control" and thus cause ______. 27. The effects of ionizing radiation doses is measured using the ______(which measures the amount of energy that the radiating transfers) and the ______(which measures the effect of radiation on living things). One gray of beta or gamma radiation is equivalent _____ Sv in its effect on living

< 08e190a81a62562d5c94a9657da19b5f.doc - Page 1 of 2 things, but one gray of alpha radiation is equal to ____ Sv. You should get exposed to no more than ______Sv of radiation per year. 28. To protect yourself from radiation, use sunscreen to block ______rays, and keep your distance from ionizing radiation, as well as minimize the amount of ______you spend in the presence of radiation. 29. Radiation is useful in medicine, as ______can be used to show broken bones or decaying teeth. The pictures take using X-rays are called ______. Bones appear lighter on radiographs because X-rays are ______by bones before they can expose the film. 30. Radioactive isotopes can be used to track the flow of blood through a patient to show, for example, a clogged coronary artery. The radioactive isotopes used emit ______rays that can be detected using special cameras.. 31. Radiation is used to treat certain disorders of the ______gland (a gland near the base of your neck that releases the hormone thyroxin, which speeds up cell metabolism). Radioactive iodine-131 is injected into the person. It travels to the thyroid gland, where it emits ______particle to destroy part of the overactive thyroid gland. 32. Some ______can be treated using radiation. For example, bone cancer can be treated by injecting radioactive strontium-89 into the patient's blood. Bones absorb the strontium just like they normally would calcium, and the beta emissions from the strontium-89 kill the cancer cells. Radiation "guns" that emit X-rays or gamma rays can also be aimed right at the tumor to kill the cancer. Unfortunately, radiation treatment also effects ______cells, and so patients often become very sick during the course of treatment. 33. ______showed that mass and energy are related by the famous equation E = mc2, where "c" stands for the speed of ______. This equation says that a little bit of ______can be converted into a lot of ______. 34. When a large nucleus decays into two or more pieces, this is called nuclear ______. Uranium, for example, can be split by firing ______at uranium nuclei. In the process, some of the mass of the uranium's decay products is converted into large amounts of ______. The fission of uranium also produces more neutrons that can go on to cause similar fission reactions to take place in surrounding cells. This is called a ______, because some of the products of the reaction go on to cause more reactions to occur. Fission reactions like this one are used to power nuclear ______(and atomic ______). To get a chain reaction to proceed, you need a certain mass of fissionable material. This amount is called the ______mass. If there is enough of the fissionable material around, the chain reaction can be ______, resulting in an explosion. 35. A nuclear reactor uses a ______fission chain reaction to produce energy. In a reactor, ______are used to slow down neutrons so that they can strike other nuclei and keep the chain reaction going. Heavy water (deuterium oxide) is often used as a moderator. Fuel rods made of ______are separated by ______rods (which control the chain reaction) made usually of cadmium or boron, which absorb excess neutrons, and can prevent a reactor meltdown. The energy release by the fission reaction is used to heat water to make steam to drive turbines to produce ______. 36. Nuclear reactors produce a lot of energy and are useful where there are no other sources of electricity. They also don't pollute the air. However, they are expensive, only last about 35 years, produce toxic nuclear ______that can be dangerous for hundreds of thousands of years, and can cause terrible damage if there is an accident causes a reactor ______like there was in 1986 at Chernobyl. 37. Nuclear fusion is a different type of reaction. In nuclear fusion, ______nuclei are fused together to form ______nuclei. In the process, a great deal of energy can be made. This is the type of reaction that takes place within the sun and stars, as well as within hydrogen bombs. A typical nuclear fusion reaction fuses ______atoms together.

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