Physics 2.5 Checklist for internal

Plum pudding model

Thomson's model of the atom in which electrons are embedded in a uniform sphere of positive charge

Rutherford's Explanation

Rutherford's experiment with gold foil that led to the discovery of the nucleus and the mostly empty space in an atom

Alpha radiation (α)

Positively charged particles consisting of 2 protons and 2 neutrons, essentially the nucleus of a helium atom

Beta radiation (β)

High-speed electrons emitted when a neutron in the nucleus breaks down into a proton

Gamma radiation (γ)

Electromagnetic radiation with high energy and no mass or charge

Ionising

The process where radiation detaches electrons from substances it interacts with

Radiation sickness

Health risks associated with exposure to radiation, including cancer, DNA mutation, burns, and acute exposure symptoms

Smoke detectors

Devices that use alpha particles to ionize molecules in the air, detecting the presence of smoke and triggering an alarm

Dosimeters

Devices used to measure and record exposure to different types of radiation, indicated by darkening of specific parts of a film

Radioactive decay

The process in which an unstable nucleus releases energy and radiation to become more stable

Alpha decay

Radioactive decay in which an alpha particle is emitted, resulting in a decrease of 4 in the mass number and 2 in the atomic number

Beta decay

Radioactive decay in which a neutron in the nucleus turns into a proton, resulting in no change in the mass number and an increase of 1 in the atomic number

Gamma decay (Gamma emission)

Radioactive decay in which gamma rays are emitted, resulting in no change in the mass number or atomic number

Half life of radioactive materials

The time it takes for half of a radioactive substance to decay into its daughter nucleus

Half life graphs

Graphs that show the decay