Atomic Physics - IB MYP Grade 10 Study Guide

These flashcards cover essential vocabulary and definitions in Atomic Physics for the IB MYP Grade 10 syllabus.

Atom

Smallest particle of an element retaining its chemical properties.

Nucleus

Central dense core of an atom containing protons and neutrons.

Proton

Positive subatomic particle in the nucleus; defines the element.

Neutron

Neutral subatomic particle in the nucleus; determines isotope.

Electron

Negative subatomic particle orbiting the nucleus in shells.

Atomic number (Z)

Number of protons in the nucleus.

Mass number (A)

Total number of protons + neutrons (nucleons).

Isotope

Atoms of same element with different neutron numbers.

Ion

Atom with unequal numbers of protons and electrons (charged).

Radioactivity

Spontaneous, random emission of radiation from unstable nuclei.

Alpha particle (α)

Helium-4 nucleus; charge +2; stopped by paper.

Beta particle (β)

Fast electron from nucleus; charge -1; stopped by aluminium.

Gamma ray (γ)

High-energy EM radiation; no charge/mass; reduced by lead.

Half-life (t½)

Time for activity (or nuclei count) of a sample to halve.

Transmutation

Change of one element to another due to nuclear decay.

Background radiation

Low-level radiation always present in the environment.

Ionisation

Removal of electrons from atoms, creating ions.

Activity

Number of nuclear decays per second, measured in Becquerels (Bq).

Fission

Splitting of heavy nuclei (e.g., U-235) releasing energy.

Nucleon

Any particle found in the nucleus — protons and neutrons.

Nucleon number

Another name for mass number.

Cation

Positive ion formed by losing electrons.

Anion

Negative ion formed by gaining electrons.

Decay graph

Shows the characteristic exponential decay curve of a radioactive substance.

Radiocarbon dating

Method using C-14 to measure the age of organic materials.

Penetrating power

Ability of radiation types to go through materials.

K radiation

Term sometimes used for gamma rays in radiography contexts.

Safety measures in radiation

Include time, distance, and shielding to minimize exposure.