Nuclear Chemistry & Radiation Vocabulary

Vocabulary flashcards covering key terms related to nuclear radiation, decay processes, and safety measures from the lecture notes.

Nuclear Chemistry

The branch of chemistry that studies changes in atomic nuclei and the use of radioactive substances.

Radiation

Small particles or energy emitted by unstable nuclei to reach a more stable state.

Natural Radioactivity

Spontaneous emission of radiation from an unstable nucleus found in nature.

Radioisotope

An isotope with an unstable nucleus that emits radiation; its name includes its mass number (e.g., Carbon-14).

Stable Isotope

An isotope whose nucleus does not spontaneously emit radiation.

Alpha Particle (α)

A helium nucleus (2 protons, 2 neutrons) with mass number 4 and charge 2 +; low-energy relative to other particles.

Beta Particle (β)

A high-energy electron with mass number 0 and charge 1 −; produced when a neutron changes to a proton.

Positron (β⁺)

A positively charged electron with mass number 0 and charge 1 +; formed when a proton converts to a neutron.

Gamma Ray (γ)

High-energy electromagnetic radiation with mass number 0 and charge 0, emitted from excited nuclei.

Mass Number (A)

The total number of protons and neutrons in a nucleus.

Atomic Number (Z)

The number of protons in a nucleus; identifies the element.

Radioactive Decay

The process by which an unstable nucleus loses energy by emitting radiation.

Nuclear Equation

A symbolic representation of a nuclear reaction showing atomic symbols, mass numbers, and atomic numbers.

Balanced Nuclear Equation

A nuclear equation in which the sums of mass numbers and atomic numbers are equal on both sides.

Alpha Decay

A decay process that emits an alpha particle, decreasing the parent nucleus’s mass number by 4 and atomic number by 2.

Beta Decay

A decay process that emits a beta particle, increasing the atomic number by 1 while the mass number remains unchanged.

Positron Emission

A decay process in which a proton becomes a neutron and a positron, lowering the atomic number by 1 with no change in mass number.

Gamma Emission

The release of pure energy from an excited nucleus; neither mass number nor atomic number changes.

Ionizing Radiation

Radiation that can remove electrons from atoms, damaging rapidly dividing cells such as bone marrow and cancer cells.

Radiation Shielding

Materials used to protect against radiation: paper/clothing for α, lab coat or heavy clothing for β, lead or thick concrete for γ.

Tissue Penetration Depth

Approximate depth radiation can travel in the body: α ≈ 0.05 mm, β ≈ 4–5 mm, γ ≥ 50 cm.

Producing Radioisotopes

Creating radioactive isotopes by bombarding stable nuclei with high-speed particles (α, protons, neutrons, or small nuclei).

Radiation Technologist

A healthcare professional who uses nuclear medicine imaging and treatments in hospitals or imaging centers.