Physics Unit 1 Vocabulary/Formulas

Ionising radiation and nuclear reactions, heating processes, electric circuits

Neutron

A subatomic particle without a charge (found in the nucleus)

Proton

A subatomic particle with a positive charge (found in the nucleus)

Electron

A subatomic particle with a negative charge (found in electron shells)

Antineutrino

a tiny, neutral and almost massless particle that is always seen in association with an electron

Neutrino

a tiny, neutral and almost massless particle that is always seen in association with a positron.

Positron

Positive electrons emitted from a nucleus

Alpha decay

occurs when there is too much mass

Beta Positive Decay (positron decay)

• Too many protons in the nucleus for the number of neutrons

• Nucleons do not change, but when the number of protons decreases, a protons changes into a neutron

• Positron and electron neutrino ejected

Beta Negative Decay

• To many neutrons in the nucleus for the number of protons

• A neutron converts into a proton

• emits and electron and an electron antineutrino

Gamma Decay

• Occurs when an atomic nucleus drops from a high-energy (excited) state to a lower energy (ground) state, releasing gamma radiation

Chemical Equations for Decay Reactions

• Parent nucleus → daughter nucleus → particle(s)

Radioactivity

Occurs when a nuclide is unstable, undergoes changes in its nucleus

Nuclear radiation

Occurs when a nuclide undergoes nuclear decay and emits radiation

Types of nuclear radiation

Alpha, Beta Positive, Beta Negative, Gamma

Alpha Radiation

• Has a 2+ charge

• Helium nuclei