Chapter 2 Nuclei and Radioactivity Radioactivity Nuclei Radioactivity is the explosion of the atomic nucleus The core of an atom holds 99 of its mass The degree from the explosion is called radiation Radiation includes Gamma Rays Alpha Particles Beta Particles The nucleus of an atom us made up of protons and neutrons and those things are made up of quarks Elements di er in their number of protons Ions di er in the number of electrons Isotopes of the same element have di erent numbers of neutrons Radiation can cause sickness Most material is radioactive Radioactivity is used to find the age of old objects such as rocks and bones For every Half life half of the nuclei decays Book Quiz practice Questions 1 Energy in the sun is produced primarily by A B C D fossil rules neutrinos fission fusion 2 The mass of the nucleus is the closest to A 99 of that of the entire atom B 1 of that in the atom C 10 5 of that in the atom D 10 15 of that in the atom 3 Radioactivity in the Earth leads to A energy for volcanos B helium for toy balloons C heat for geysers D all of the above 4 LD50 refers to a lethal dose legal dose large dose lowest dose A B C D 5 A major reason that your body is radioactive is that A it is slightly contaminated by debris from nuclear tests it is made radioactive my medical x rays B C you eat radioactive carbon in your food D you are hit by neurons from the Sun 9 6 The primary cause of death from the Hiroshima bomb was A B C D radiation induced cancer the blast from the bomb fallout from the bomb smoking induced by fear of the bomb 7 Fission fragments are A harmless particles emitted in radioactivity B among the most dangerous kind of radiation C ghost like particles that pass through the Earth D the source of the most energy in the Sun 8 Wine made from fossil rules is not radioactive because the radioactivity has decayed away there is no carbon in such wine A B C ancient planets never were radioactive D the half lime of the key elements is too long If the half life of an element is big that means that it decays faster than one with a small half life A It decays it slower than one with a small half life B it belongs to a very heavy element C it emits lots of neutrons when it decays D 10 Muller wears a wristwatch with tritium in the watch hands because tritium is not radioactive A he is not worried about radioactivity B C The levels of radiation that emerge are safe D New radiation emerges from the watch hands 11 After three half lights the fraction of nuclei remaining is A 1 2 B 1 3 C 1 4 D 1 8 12 Most of the elements found on the Earth were created in the first few million years of the Earth s existence A B within the star in the Big Bang C in a supernova explosion D 13 The fraction of the U S population that dies from cancer is typically A about 1 in 10 000 B about 1 in 100 C about 1 in 5 D Mist of us die from cancer 14 Watch dials containing radium glow because 16 After four half lives the surviving tritium atoms are removed Compared to completely new tritium adams 17 One rem of radiation dose takes how many gammas per square centimeter A all radioactivity creates light B batteries supply energy when a button is pushed C the right radiation hits a phosphor D They don t glow Only tritium glows 15 Choose all the items that derived from radioactivity A helium for children s balloons B volcanic lava C warmth deep mines D most cancer in the United States they are expected to live A 1 8 as long B 1 4 as long C 1 2 as long D exactly as long A about 1 B about 5000 C about a million D about 2 000 000 000 18 Which requires the larger dose radiation poisoning cancer A B C They are very close in the amount needed 19 The linear hypothesis is choose all that are correct A known to be true B widely used even though it is not proven C known to be false D generally ignored in analysis of radiation deaths 20 A Sievert is how many rem A 1 B 0 01 C 100 D 1000 21 Cancer is lower in Denver because the radiation is lower the radiation is higher there are more gamma rays even though there are fewer betas A B C D We don t know why 22 The number of deaths from the Chernobyl accident is about less than 1 A B 24 000 C 124 000 D over a million 23 Radioactivity is used in A flashlights B TV screens C florescent lights smoke detectors D 24 Neutron activation is used to treat cancer to search for rare atoms to provide energy to create light A B C D 25 Dirty bombs maybe less of a threat than people fear because A once spread out the rem level drops below the radiation illness threshold B dirty bombs required for Tony and that is hard for terrorists to obtain C D the radioactivity is too small to reduce cancer the radiation does not actually get out of the bomb case even when exploded 26 Radioactivity in the earth is responsible for A helium we use in balloons B warmth to keep the oceans liquid C creation of the oxygen we breathe D navigation of birds 27 Volcanic heat comes from radioactive explosions A B the weight of rock C accumulated sunlight D fusion deep in the earth 28 The best way to measure the age of an ancient bone is A potassium argon dating B neutron activation C controlled thermonuclear fusion D radiocarbon dating 29 An RTG radioscopic thermoelectric generator is A a type of bomb B used in hospitals for power C carried in pacemakers to supply power D carried in satellites for power 30 Uranium is found on Earth even though it is radioactive That s because A B C D it is constantly made by cosmic rays It has a very long half life it is created infusion in the sun it is created by fusion in the Earth 31 Carbon 14 compared to Carbon 12 A has more protons B has more neutrons C has more electrons D has a shorter half life 32 Alexander Litvinenko was assassinated with A plutonium tritium B C radium D polonium 33 The radiation from cell phones A does not cause cancer B C causes over 1 of the cancer in those who use them D protects users from cosmic rays causes cancer but not enough to worry 34 The threshold for radiation illness is about A 1 rem B 100 rem C 500 rem D 2500 rem …
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