IGCSE Edexcel Physics: Radioactivity Complete Study Guide

These flashcards cover key vocabulary and definitions related to radioactivity as outlined in the IGCSE Edexcel Physics study guide.

Becquerel (Bq)

Unit of measurement for the activity of a radioactive source, equal to one decay per second.

Atomic Number (Z)

Number of protons in the nucleus of an atom, which determines the element.

Mass Number (A)

Total number of protons and neutrons in the nucleus of an atom.

Isotope

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Alpha Radiation (α)

Type of ionizing radiation that consists of helium nuclei.

Beta Radiation (β⁻)

Type of ionizing radiation consisting of fast-moving electrons.

Gamma Radiation (γ)

Electromagnetic radiation emitted from a nucleus.

Penetrating Power

Ability of radiation to pass through materials; varies between alpha, beta, and gamma radiation.

Half-Life

The time taken for the activity of a radioactive substance to halve.

Radiation Sources from Earth

Includes rocks, soil, radon gas, and radioactive elements in food.

Radiation Detection Method: Geiger-Müller Tube

Device that ionizes gas, producing pulses of current counted to measure radiation.

Contamination vs Irradiation

Contamination refers to radioactive material on/in the body; irradiation is exposure to external radiation.

Nuclear Fission

Process of splitting heavy atomic nuclei to release energy.

Control Rods

Materials used in a nuclear reactor to absorb neutrons and manage the fission process.

Nuclear Fusion

Process of combining light atomic nuclei to form a heavier nucleus, releasing energy.

Electrostatic Repulsion

Phenomenon where positively charged protons repel each other, requiring high energy for fusion.