Paper 1 - Topic 4, Atomic Structure Flashcards
What is activity
The rate at which an unstable nucleus decays
What is an alpha particle
A positively charged particle consisting of two protons and two neutrons
What is the atomic number
The number of protons found in an atom of a specific element
What is background radiation
Radiation that is found in small quantities all around us and originates from natural resources such as rocks and cosmic rays as well as man-made resources like nuclear weapons testing and accidents
What is a beta particle
A high speed electron that a nucleus emits when a neutron converts into a proton
What is a chain reaction
The process of neutrons released by a fission reaction being absorbed by another unstable large nuclei and inducing further fission
What is the count-rate
The number of decays that a detector measures per second
What is an electron
Negatively charged particle that orbits around the nucleus in shells
What are the products of fission
Fission produces two smaller nuclei, two or three neutrons and gamma rays, these products are released with kinetic energy
What is a gamma ray
Electromagnetic radiation emitted from a nucleus
What is half-life
The time it takes for the number of unstable nuclei of an isotope in a sample to halve, or the time it takes for the initial count rate of a sample of the isotope to halve
What are ions
Atoms with a resultant charge due to the loss or gain of electrons
What is irradiation
The process of an object being exposed to nuclear radiation, the object doesn’t become radioactive
What are isotopes
Atoms with the same number of protons but different numbers of neutrons
What is the mass number
The number of protons and neutrons in an atom
What are negative ions
Atoms that gained electron(s) and so have a resultant negative charge
What are neutrons
A neutrally charged part of the nucleus
What is nuclear fission
The splitting of a large and unstable nucleus into two smaller and more stable nuclei to produce energy
What is nuclear fusion
The joining of two small, light nuclei to form a larger heavier one and release energy
What is the plum pudding model
An old model of the atom that represented the atom as a ball of positive charge with negative charges distributed throughout it
What are positive ions
Atoms that have lost electrons and so have a resultant positive charge
What are protons
A positively charged part of the nucleus
What is radioactive contamination
The unwanted presence of radioactive atoms on other materials, it is h dangerous due to the decay of the contaminating atoms
What is radioactive decay
The random process involving unstable nuclei emitting radiation to become more stable
