Key vocabulary

◆ Radioactivity Spontaneous transmutation of an unstable nucleus, accompanied by the emission of ionizing radiation in the form

of alpha particles, beta particles or gamma rays.

◆ Transmutation When a nuclide changes to form a different element after emitting a particle.

◆ Radioactive Describes a substance which contains unstable nuclei which will emit radiation.

◆ Radioisotope or radionuclide Isotope / nuclide with an unstable nucleus which emits radiation.

◆ Daughter product

The resulting nuclide after a radionuclide (‘parent’) emits a particle.

◆ Geiger–Muller tube Apparatus used with a counter or ratemeter to measure the radiation from a radioactive source.

◆ Count rate (radioactivity) The number of nuclear radiation events detected in a given time (per minute or per second).

◆ Ratemeter Meter which is connected to a Geiger– Muller tube (or similar) to measure the rate at which radiation is detected.

◆ Background radiation Radiation from radioactive materials in rocks, soil and building materials, as well as cosmic radiation from space and any radiation escaping from artificial sources.

◆ Background count Measure of background radiation.

◆ Beta particle A high- speed electron that is released from a nucleus during beta negative decay, or a high-speed positron released during beta positive decay.

   Nuclear equation An equation representing

a nuclear reaction. The sum of nucleon numbers (A) on the left-hand side of the nuclear equation must equal the sum of the nucleon numbers on the right-hand side of the equation. Similarly with proton numbers (Z).

◆ Radioactive decay equation Balanced nuclear equation which shows

a radionuclide and its decay products.

◆ Penetrating power

The penetrating power of nuclear radiation depends upon the ionizing power of the radiation. The radiation continues to penetrate matter until it has lost (nearly) all of its energy. The greater the ionization per cm, the less penetrating power it will possess.

◆ Ionizing ability A measure of how much ionization is caused when a particular type of radiation passes through a material.

Antiparticle Every particle has an antiparticle with opposite physical properties.

◆ Antimatter Matter consisting of antiparticles.

◆ Antineutrino Low- mass, uncharged and very weakly interacting particle emitted during beta-negative decay. Antiparticle of neutrino.

◆ Annihilation When a particle and its antiparticle interact, their mass is totally converted to electromagnetic energy.

◆ Neutrino Low-mass, and very weakly interacting uncharged particle emitted during beta-positive

decay. Antiparticle of antineutrino.

Beta-negative decay Radioactive decay resulting in the emission of an electron (and an antineutrino)

◆ Beta-positive decay Radioactive decay resulting in the emission of a positron (and a neutrino).

◆ Positron Antiparticle

of the electron; released during beta-positive decay.

◆ Gamma radiation / ray Electromagnetic radiation (photons) emitted from some radionuclides and having an extremely short wavelength.

◆ Chart of nuclides A chart which displays every possible nuclide on axes of proton number and neutron number.

Three new things I learned:

1. Because a beam of alpha particles, or beta particles, is a flow of charge they will be deflected if they pass across a an electric field or magnetic field

2. Every nuclide can be placed on a chart of nuclides, which has a square for every possible combination of photon number and neutron number

3. Individual nuclei do not decay in any pattern (the decays are random) and each decay occurs without any obvious cause, (the decays are spontaneous).