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science test 8th
test for 3/12/12
Question | Answer |
---|---|
discovered radioactivity,hypothesis is that radioactivity is "invisible energy emitting from ore" | becquerie |
students of becquerie, studied "invisible energy",coined word radioactivity, made 1st synthetic elements | Pierre and Marie Currie |
first synthetic elements made | Radium and polonium |
the release of particles and energy from an unstable nuclei | radioactivity |
the number of protons doesnt equal number of neutrons | unstability |
an element with a specific atomic mass and specific atomic number | nuclide |
spontanious breahdown of the nuclei | radioactive decay |
one element turning into another element | transmutation |
weakest form of radiation,made of 2 protons and 2 neutrons,positive particle,helium nucleus,can be stopped by a single sheet of paper | alpha particle |
negative charged particle,100x more penetration power,x-rays are created during _____ decay, can be stopped by 1cm of Al | beta particle |
not a particle,travels in waves,high frequency,short wavelength,cellular damage,can be stopped by high dense matter like pb | gamma radiation |
the time it takes for half of the radioactivity sample to decay | half life |
the atoms that undergo fission in the reactor | fuel supply |
pb "tylenol" around the core,secondary _________ unit structure is high density concreate | containment |
slows down the speed of neutrons to increase the accuracy of the hit,in the US heavy H2O | moderator |
rver water is constantly pouring over the core carrying heat away,helps control temps. | coolant |
controls the rate of the fission reaction,act like magnet to absorb neutrons to speed up/slow or stop chain reaction,in US boron and cadmium | control rods |
uses an electric current to detect radiation, glass tube filled with Ar or He with W wire running through it | geiger counter |
super saturated water vaper in a clean chamber, introduce radiation and leaves" cloud tracks" everywhere radiation was | cloud chamber |
fill a chamber with liquid just below boiling point,introduce radiation and bubble from everywhere radiation was | bubble chamber |
plate coated with AgBr, introduce radiation, reacts with AgBr to make a negative image of radiation pattern | nuclear emulsion |
during this, a helium nucleus is released form an unstable nucleus | alpha decay |
protons and neutrons are held together by this in a nucleus | binding energy |
an element with unstable nuclei produces this | radioactivity |
a neutron changes into a proton during this | beta decay |
the release of alpha particles is one kind of this | radioactive decay |
the most energetic type of radioactive decay is this | gamma decay |
when a nucleus of uranium-235 undergoes this 2 smaller nuclei result | nuclear fission |