Ch 18 Study Guide 10/8/14 Flashcards
a ____ occurs when neutrons released from a nucleus splitting, split other nuclei
chain reaction
a proton or a neutron
nucleon
when a radioactive nucleus emits and alpha particle, its atomic number
decreases by two
the most widely used radioactive isotope used in nuclear medicine
technetium-99
fusion occurs in __
the sun
when a radioactive nucleus emits an alpha particle, its mass number ___________
decreases by four
a high energy electron realeased by a nucleus is called a
beta particle
the radioisotope used for dating objects made of materials that were once alive
carbon-14
when a radioactive nucleus emits a beta particle the atomic number ______
increases by one
the penetrating rays and particles emitted by a radioactive source
radiation
the high energy photon emitted by a nucleus during fission and radioactive decay
gamma ray
an isotope that has unstable nucleus and undergoes radioactive decay
radioisotope
a few centimeters of this can stop gamma radiation
lead
the use of radioactive isotopes to determine the age of an object is called
radioactive dating
a general term applied to a specific nucleus with a given number of protons and neutrons
nuclide
the most penetrating form of radiation
gamma
the type of nuclear reaction that occurs in nuclear power plants
fission
the stable nuclei on a neutron-versus-proton plat are located in the ______
band of stability
the nuclear reaction that powers the sun and all the stars
fusion
a particle with the mass of an electron but a positive charge that is emitted when a proton turns into a neutron
positron
protons and neutrons are made up of
quarks
the time it takes for half of the radioisotope to decay
halflife
the minimum mass of a fissionable isotope that provides the number of neutrons needed to sustain a chain reaction
critical mass
the energy released when nucleons come together is called
nuclear binding energy
alpha particles have a ____ penetrating power
low
this can be both caused by radiation and cured by it
cancer
nuclei with ____ numbers of neutrons and protons are more stable
even
no nuclei with atomic number greater than ____ and a mass number larger than 209 are stable
83
in this type of radiation smaller nuclei are combine together creating larger nucleus
fusion
this type of radiation is easily stopped by your skin, but is very dangerous when ingested
alpha
a medical procedure that uses radioisotopes with short half lives to get three dimensional images of organs
PET
this type of radiation contains two protons and two neutrons and has a positive two charges
alpha
used in nuclear power plants to adjust the rate of the chain reaction by absorbing neutrons
control rod
a unit of radiation
rem
this type of radiation has moderate penetrating power
beta
the process in which an unstable nucleus emits on or more particles or energy in the form of electromagnetic radiation
radioactivity
the part of a nuclear power plant that reduced the speed of neutrons so they can be captured by the reactor fuel in order to continue the chain reaction
moderator
the top number of an isotope symbol is the element’s ___
mass number
the splitting of large nuclei into smaller nuclei
fission
a few sheets of this can be used to stop beta particles
aluminum foil
the interaction that binds nucleons together in the nucleus
strong force
nuclei may be unstable because they have ____ neutrons relative to the number of protons
too many
1/1 H, 1/+1 p
proton symbols
0/+1 e
positron
0/-1 e
beta particle
4/2 He
alpha
y, 0
gamma ray
what is beta stopped by?
few sheets of aluminum foil
what is a positron stopped by?
few sheet of aluminum foil
what is alpha stopped by?
skin or one sheet of paper
what is gamma stopped by?
several centimeters of lead
what is neutron stopped by?
few centimeter of lead
what is proton stopped by?
few sheets of paper
which has least, most or moderate penetration power?
least= alpha
most=gamma
moderate=beta
what makes nuclei stable
nuclei are stable if its neutron to proton ratio is 1 n/z= 1
what make a nuclei unstable?
when n/z is not 1 or 1.5
why are some elements magic numbers?
because the tend to be more stable than others
famous formula…
e=mc^2
why are things radioactive?
because they want to become stable
what force overcomes radiation?
strong force
remeber decay or emission is blah blah —–> here
and bombarded or collide is here—–>blah blah
remeber that!!!!!!!
remeber decay or emission is blah blah —–> here
and bombarded or collide is here—–>blah blah
