Nuclear Chemistry and Radioactivity Flashcards

Which conservation law requires that the mass numbers balance in a nuclear equation?

Answer: Conservation of mass number and atomic number

In nuclear equations, both the total mass number (nucleons) and total atomic number (charge) must be equal on both sides of the equation.

Nuclear fission is best described as:

Answer: A heavy nucleus splitting into two smaller nuclei

Nuclear fission involves the splitting of a heavy nucleus (like uranium-235) into two smaller nuclei, releasing a large amount of energy.

Carbon-14 radioactive dating is useful for determining:

Answer: The age of organic (carbon-containing) materials up to ~50,000 years old

Carbon-14 (half-life ~5,730 years) is incorporated into living organisms; after death the C-14 decays, allowing age estimation up to about 50,000 years.

Gamma radiation differs from alpha and beta radiation in that gamma radiation:

Answer: Is electromagnetic radiation with no mass or charge

Gamma rays are high-frequency electromagnetic waves (photons) with no rest mass and no electric charge, unlike alpha (+2) and beta (−1) particles.

In beta-minus decay, a neutron is converted inside the nucleus into:

Answer: A proton and an emitted electron (beta particle)

Beta-minus decay: n → p + e⁻ + antineutrino; the proton stays in the nucleus and the electron (beta particle) is emitted.

What is a nuclear chain reaction?

Answer: A process where neutrons from fission trigger additional fissions, releasing more neutrons

In a chain reaction, each fission event releases neutrons that cause further fissions, creating a self-sustaining cascade of reactions.

Which isotope notation correctly represents an alpha particle?

Answer: ₂⁴He

An alpha particle is written as ₂⁴He because it contains 2 protons (atomic number 2) and a mass number of 4 (2 protons + 2 neutrons).