chem test Flashcards
the repulsion between like charged particles
electromagnetic force
two protons and two neutrons bound together
alpha particle
the number of neutrons compared to protons that a nuclide has
neutron to proton ratio
the time it takes for half of a radioactive sample to decay
half-life
radiating which can remove electrons from atoms and molecules
ionizing radiation
the result of a fission reaction
daughter nuclei
the ability of radiation to pass through solid material
penetration power
radiation which comes from the stars and the sun
cosmic radiation
high energy electromagnetic waves
gamma-ray
radioactive decay into a different isotope
transmutation
the process of a heavy nucleus splitting into two or more lighter nuclei
fission
radiation which can be found throughout nature
terrestrial radiation
a neutron that has been converted into a proton, an electron, and a neutrino
beta particle
when two nuclei become one, heavier nucleus
fusion
the creation of a new nucleus
nucleogenesis
in which type of nuclear decay does the atomic number remain the same
gamma decay
radioactivity which is in the form of high energy waves is known as
gamma decay
when a radioisotope changes from element to another it is called
transmutation
Tritium (^3H) undergoes beta decay. the element which is produced is
helium
nuclear power-plants work on the basis of
nuclear fission
which of the following is not true of the nuclear strong force
it is weaker than the electromagnetic force
the two elements formed in the big bang nucleosynthesis were
hydrogen and helium
the ratio of elements found after the big bang was
75% hydrogen and 25% helium
what conditions are required for nuclear fusion
extreme temperature and pressure
after three half-lives, how much of radioactive sample will remain
12.5%
when sodium-24 decays it does so by beta emission, gamma radiation is also released. write the equation for the decay of sodium-24 by beta emission.
2411Na –> 2412Mg+01e
define the term half-life as it applies to sodium-24
it takes 15 hours for half of a sample of sodium-24 to decay into Magnesium-24
a sample of sodium-24 with a mass of 20g undergoes radioactive decay. calculate the amount of sodium left after 60 hours give your answer as a percentage.
60/15= 4 half lives
(1/2)^4 x 20=1.25g
6.25%
there are 21 recognized isotopes of sodium, with ass numbers ranging from 18-39. only one of these, sodium-23 is stable. explain why sodium-23 is stable in terms of: it’s neutron to proton ration and the band of stability
sodium-23 has a ratio of 11:12. it’s close to a ratio of 1:1. it fits into the band of stability.
there are 21 recognized isotopes of sodium, with ass numbers ranging from 18-39. only one of these, sodium-23 is stable. explain why sodium-23 is stable in terms of: the forces operating in its nucleus
the strong nuclear force works against the repulsion to make it stable
sodium-24 is used in diagnostic medicine as a tracer to detect blood clots: what is a tracer
a tracer, a radioactive element, is used to find issues in the body through imaging
sodium-24 is used in diagnostic medicine as a tracer to detect blood clots: how does a tracer work?
tracers are inserted through ivs or injected when inside the body. tracers emits particles that can be imaged (via PET scans)
sodium-24 is used in diagnostic medicine as a tracer to detect blood clots: describe the application of another named radioisotope which is used in either medicine or industry
carbon-14: how old something is
describe the process of nuclear fusion
nuclear fusion is the process of two smaller nuclei joining or fusing together to form a heavier nucleus
where does this process of nuclear fusion occur
stars/sun
explain why nuclear fusion requires extreme temperature and pressure
this reaction requires extreme temperature and pressure to overcome the electrostatic or repulsion forces.
nucleosynthesis occurred in the big bang to form the first nuclei. describe this process and name the two nuclei that were initially formed as part of this process
the process of creating new nuclei from existing protons and neutrons like helium and hydrogen
explain how nuclear fission differs to nuclear fusion. include the equation for the nuclear fission of uranium
fission splits them apart and needs a neutron. fusion puts them together and needs high heat and pressure.
if it is in the sun then its
nuclear fusion
the first elements were formed by
the big bang nucleosynthesis
alpha reduces atomic number by
2
repulsion is greater than nuclear force than it is
unstable
