Nuclear Chemistry

Miscellaneous

100

What are isotopes? Give an example of 2.

Isotopes are nuclides with the same number of protons but varying numbers of neutrons, and therefore, mass numbers.

C-12, C-14

200

Nuclear reactions involve changes in numbers of which particles? 

Bonus points for the word that describes them both.

Protons and neutrons

Nucleons

300

Which radioisotope would be useful in dating a mummy from ancient egypt? 

a) I-131      b) K-37

c) N-16       d) C-14

Carbon-14

400

Which type of particle is emitted as a sample of technium-99 naturally decays?

B^- , beta particle

500

Calculate the average atomic mass for element X, based on the ratios of it's 3 isotopes.

64.3% X-19

20.8% X-20

14.9% X-22

Average mass = 19.7

Nuclear Reactions

100

Four types of nuclear radiation that can be produced in a natural decay.

alpha, beta, gamma, positron

200

What is the main benefit fusion and fission reactions?

huge amounts of energy produced per mole of reactant.

300

Productive uses for nuclear chemistry

What are medicine, energy, food irradiation

400

Explain the difference between artificial and natural transmutation.

Natural transmutations occur spontaneously to achieve stability.

Artificial transmutations are the results of a stable isotope becoming unstable by bombardment of radiation.

500

In a decay series of thorium-232, the first four decays are as follows; alpha, beta, beta, and alpha emissions. Write the nuclear equations for this series of reactions.

₉₀²³²Th -> a + ₈₈²²⁸Ra -> B^- +₈₉²²⁸Ac -> 

B^- + ₉₀²²⁸Th -> a + ₈₈²²⁴Ra

Half-Life

100

What is half-life

Average time it takes for half the amount of a radioactive element to decay

200

Thorium-234 has a half-life of 24 days, started with 100 g how much is left after 48 days?

25 grams of thorium-234 remain

300

Plutonium-239 is 2.410 x 10⁴ years how much of 70 g remains after 9.64 x 10⁴ years?

4.375 grams of Plutonium-239 remain

400

Radium-266 has a half life of 1599 years, how many years have passed if only 1/32 of the original sample remains?

7995 years have passed

500

Francium - 220 and Krypton - 85 are both radioactive isotopes. Using this information, and ref. table N, explain which of these two isotopes is more radioactive, and why.

Fr-220 has a shorter half-life and is therefore more radioactive.

Fission

100

What is fission?

a nuclear reaction that invlolves the splitting of a heavy nucleus into a lighter nucleus.

200

Which element is typically the fuel in a fission reaction?

Uranium - 235

300

Least penetrating form of radiation

What is an alpha particle

400

When can mass be converted to energy?

When a nuclei splits 

500

Critical mass states that you need a minimum mass of a fissionable isotope in order to provide enough neutrons to continue the reaction. This continuation of the fission reaction is known as a ____________.

Chain reaction

Fusion

100

What is fusion?

Two smaller nuclei combining to form a larger nucleus, releasing tremendous amounts of energy. Type of reaction that occurs in the stars.

200

What are the requirements for fusion reactions?

Very high temperatures

High pressure

300

What are the downsides of using fission as an energy source?

nuclear waste; danger of out-of-control chain reaction

400

Compare the energy produced during a fission vs the energy produced in a fusion reaction.

Fusion > Fission

Fusion produces much more energy.

500

In a particle accelerator, which 2 particles can be accelerated? 

Protons & electrons