Physics Lecture on Radioactivity

This set of flashcards covers key terms and concepts from the physics lecture on radioactivity, including definitions and explanations related to nuclear processes.

Radioactivity

The spontaneous emission of alpha (α), beta (β), and gamma (γ) radiation from the nucleus of unstable atoms.

Alpha particles (α)

Positively charged particles consisting of two protons and two neutrons, equivalent to a helium nucleus.

Beta particles (β)

Negatively charged high-speed electrons emitted from the nucleus of an atom during radioactive decay.

Gamma rays (γ)

High-energy electromagnetic waves emitted from the nucleus during radioactive decay, having no charge or mass.

Mass number (A)

The total number of protons and neutrons in the nucleus of an atom.

Atomic number (Z)

The number of protons in the nucleus of an atom, determining the element's identity.

Isotopes

Atoms of the same element that have the same atomic number but different mass numbers due to different numbers of neutrons.

Isobars

Atoms of different elements that have the same mass number but different atomic numbers.

Isotones

Atoms with different atomic numbers but the same number of neutrons.

Einstein's mass-energy equivalence

E=mc², the principle stating that mass can be converted to energy and vice versa.

Fission

The process of splitting a heavy nucleus into lighter nuclei with the release of a large amount of energy.

Fusion

The process of combining two light nuclei to form a heavier nucleus, also releasing a significant amount of energy.

Nuclear decay

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

Neutron

A subatomic particle found in the nucleus of an atom, having no electric charge.

Proton

A positively charged subatomic particle found in the nucleus of an atom.

Penetration power

The ability of radiation to pass through materials; higher for gamma rays than beta and alpha particles.

Ionizing power

The ability of radiation to ionize atoms, strongest in alpha particles and weakest in gamma rays.

Radiotherapy

The use of ionizing radiation to treat cancer.

Chain reaction

A sequence of reactions where a reactive product or by-product causes additional reactions to take place.

Half-life

The time required for half the quantity of a radioactive substance to decay.

Decay constant

The probability per unit time that a nucleus will decay.

Radiation shielding

Materials used to protect against radiation exposure.

Safety measures for nuclear energy

Procedures and protocols to minimize exposure and prevent accidents in nuclear facilities.