Unit 1 topic 2: ionising radiation and nuclear reactions Flashcards
Nuclear model
the model describes the atom as having a small positively charged core surrounded by negatively charged particles called electrons
nucleons
the particles (protons and neutrons) that make up the nucleus of an atom
atomic number
the total number of protons in an element’s nucleus
mass number
the total number of nucleons in an element’s nucleus
isotopes
atoms with the same number of protons but different number of neutrons
atomic mass unit
one twelth of the measured mass of a C-12 atom (including electrons)
mass defect
the difference between the mass of an intact nucleus and the sum of the masses of the individual nucleons of which it is made.
strong nuclear force
one of the four fundamental forces; the strong nuclear force acts over small distances in the nucleus to hold the nucleons together against the repulsive electrostatic forces exerted between the protons.
binding energy
the mechanical work that must be done against the forces holding a nucleus together to disassemble it into component parts.
electron volt
a unit of energy equal to the work done on an electron in accelarating it through an electron potential difference of 1 volt
WHen does alpha decay occur
When there are too many protons and neutrons
What is emitted in alpha decay
Alpha particle and gamma radiation
When does beta negative decay occur
Too many neutrons
What happens during beta negative decay
a neutron transmutes into a proton.
WHat is emitted in beta negative decay
electron, antineutrino and gamma radiation
When does beta positive decay occur
When there is too many protons
what happens during beta positive decay
a proton transmutes into a neutron
what is emitted in beta positive decay
positron, neutrino, gamma radiation
when does gamma decay occur
when nucleons are in an unfavourable configuration
what happens during gamma decay
nucleone rearrange themselves into a lower energy configuration
what is released during gamma decay
excess energy and gamma radiation
ionise meaning
electron gets knocked off the atom
As strong nuclear force increases, what happens to the number of nuclides
Number of nuclides increases
types of bombardment
proton, alpha particles, deuteron, neutron
when does nuclear fusion or fission occur?
when the products are at a lower overall energy than the reactants
artificial transmutation
the process in which an isotope is intentionally caused to change by nuclear processes into an isotope of another element
natural radioactive decay
the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays and electrons without artificial stimulus to do so
