Atomic Structure
Nuclear Particles
Trans-mutation
Fission and Fusion
Half Life
100
This subatomic particle has the same mass as a proton, but no charge.
Neutron
100
This nuclear particle has the same mass and charge as an electron.
Beta particle
100
This particle is released when iron-53 spontaneously decays.
Positron
100
A controlled version of this type of reaction takes place in a nuclear power plant.
Fission
100
Define half-life.
The amount of time it takes for 1/2 of a radioactive sample to decay.
200
These two subatomic particles add to give the mass number of an atom.
Protons and neutrons
200
This nuclear emission has the lowest penetrating power.
Alpha particle
200
This characteristic defines whether a nucleus is stable or unstable.
The ratio of neutrons to protons
200
Identify one difference between fission and fusion.
Fission: breaks apart a large nucleus into smaller nuclides, creates radioactive products, takes place on Earth in nuclear power plants or nuclear bombs... Fusion: sticks together two smaller nuclei into a larger one, no radioactive products, takes place in the sun...
200
Explain why iodine-131 is a better candidate for an ingestible radioisotope than strontium-90.
It has a shorter half-life (less time emitting radiation in your body).
300
In terms of energy levels, describe the transition that occurs when an atom or ion releases visible light. Your answer must include the name of the subatomic particle that makes the transition.
Electrons move from a higher energy level (excited state) to a lower energy level (ground state).
300
Releasing this nuclear emission results in a decrease in the atomic number by one.
Positron
300
The nucleus of this element is formed when thorium-232 decays.
Radium (Ra)
300
Write the symbol for the missing product, X. Here, the left-hand side of each symbol is written in the form (mass/charge). (235/92)U + (1/0)n --> (144/55)Cs + X + 2(1/0)n
(90/37)Rb
300
A 60-gram sample of francium-220 decays to 7.5 grams. How long does this decay take?
82.2 seconds
400
Compare the net charge on a lithium atom to the nuclear charge of a lithium atom.
The net charge (protons - electrons) of an atom is 0; the nuclear charge of lithium is +3. Regents-style would also accept "the net charge is less than the nuclear charge" (probably)
400
The radioisotope used to treat thyroid disorders decays by releasing this nuclear particle.
Beta particle
400
Write the equation for the spontaneous decay of technetium-99.
Notation is hard here, so the left-hand side represents (mass/charge): (99/43)Tc -> (0/-1)e + (99/44)Ru
400
Identify how energy is produced by fission and fusion reactions.
E = mc2 Small amounts of mass are converted into energy
400
A 10-gram sample of calcium-37 decays for just 728 milliseconds. How must of the calcium-37 remains?
0.625 grams
500
Element X has two natural isotopes. One of the two isotopes has a mass of 13.002 g/mol, while the other has a mass of 13.99 g/mol. The natural abundance of the lighter isotope is 36.4%. Calculate the weighted atomic mass of Element X.
= (13.002*.364)+(13.99*(1-.364)) = 13.63 g/mol
500
Identify a radioisotope that could have been used in the experiment that determined atoms were composed of mostly empty space.
Any radioisotope on Table N that has an alpha decay mode
500
Compare natural transmutation and artificial transmutation by listing two differences between the two processes.
Possible differences: - Natural is spontaneous, artificial is nonspontaneous - Natural has one reactant, artificial has two reactants - Natural changes an unstable nucleus, artificial changes a stable nucleus ...
500
Explain why we haven't yet been able to build nuclear fusion reactors here on Earth.
Fusion requires massive amounts of energy to force to happen and typically only takes place under extreme conditions (like those found on the Sun)
500
A games of krypton-85 decays to 31 grams in 21.46 years. What was the mass of the original sample?
124 grams
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