Chemistry: Atomic Theory and Nuclear Chemistry Review

Mr. Devlin Unit 2 Part 2

What is the nuclear force?

An attractive force acting between all nuclear particles (protons and neutrons) that holds the nucleus together.

What is the Band of Stability?

A region where stable nuclei exist; out of over 1,500 known nuclei, only 264 are stable.

What is the most stable isotope?

Iron-56 (56Fe)

What is the neutron-to-proton ratio for stable nuclei?

Nuclei of low atomic numbers with a 1:1 ratio of neutrons to protons are very stable.

What is mass defect (Δm)?

The difference between the total calculated mass of individual subatomic particles and the actual mass of the stable nucleus.

What is nuclear binding energy?

The energy required to break up a nucleus into its component protons and neutrons.

What is half-life (t1/2)?

The average time required for half of the unstable atoms in a sample to decay.

What is transmutation?

The conversion of an atom of one element into an atom of another element via radioactive decay or particle bombardment.

What is the difference between nuclear fission and fusion?

Fission is the splitting of a heavy nucleus into smaller fragments; fusion is the combining of low-mass nuclei to produce a nucleus of greater mass.

What is a chain reaction in nuclear fission?

A self-sustaining reaction where neutrons produced by fission collide with other fissionable atoms, producing more neutrons.

What is critical mass?

The minimum mass of fissionable material needed to sustain a chain reaction.

What is neutron moderation?

The process of slowing down fast neutrons so that reactor fuel can capture them to continue the chain reaction.

What is neutron absorption?

The process of decreasing/removing the number of slow-moving neutrons to prevent excess fission.

What is the half-life of Carbon-14?

5,730 years

What is the primary application of Potassium-40?

Dating ancient geological formations and rocks.

What are transuranium elements?

Elements with atomic numbers greater than 92; all are synthetic and radioactive.

What is the mass-energy equivalence formula?

E = mc², where E is energy, m is mass, and c is the speed of light.

What is the binding energy per nucleon?

The binding energy divided by the number of nucleons in the nucleus.

What is the decay formula for half-life?

N = N0 · (1/2)^x, where N is the amount left, N0 is the initial amount, and x is the number of half-lives.

What is the half-life of Molybdenum-99?

67 hours

What is the medical application of Sodium-24?

Blood-flow tracer.

What is the half-life of Technetium-99m?

6.0 hours

What is the significance of Iodine-131 in medicine?

It is used to assess thyroid gland activity.

What happens to Strontium-90 in the human body?

It concentrates in human bones due to its chemical similarity to calcium.

What is the primary fuel for nuclear fission?

Uranium-235 (235U) and Plutonium-239 (239Pu).

What are the challenges of nuclear fusion?

Requires extremely high temperatures to overcome electrostatic repulsion of positive nuclei.