ST.7 Nuclear Chemistry N5 (CIS) Flashcards
What is radioactive decay?
Radioactive decay involves changes in the nuclei of atoms
How can unstable radioisotopes become stable?
Unstable nuclei (radioisotopes) can become more stable nuclei by giving out alpha, beta or gamma radiation
Alpha particles atomic structure?
Alpha particles (α) consist of two protons and two neutrons, and carry a double positive charge
How far do alpha particles range?
Alpha particles have a range of only a few centimetres in air and are stopped by a piece of paper
What type of plate are alpha particles attracted towards?
Alpha particles will be attracted towards a negatively charged plate
What are beta particles?
Beta particles (β) are electrons ejected from the nucleus of an atom
How far do beta particles range?
Beta particles are able to travel over a metre in air but can be stopped by a thin sheet of aluminium
What type of plate are beta particles attracted towards?
Beta particles will be attracted towards a positively charged plate
What are gamma rays?
Gamma rays (γ) are electromagnetic waves emitted from within the nucleus of an atom
How far can gamma rays range?
Gamma rays can be stopped by barriers made of materials such as lead or concrete
Are gamma rays deflected by an electrical field?
Gamma rays are not deflected by an electric field
How are alpha, beta, proton and neutron particles represented?
SEE WRITTEN FLASHCARD
What is half-life?
Half-life is the time taken for half of the nuclei of a particular isotope to decay
Can half-life ever be affected by anything?
The half-life of an isotope is a constant, unaffected by chemical or physical conditions
How can the half-life of an isotope be determined?
The half-life of an isotope can be determined from a graph showing a decay curve
State 2 uses of radioisotopes
- Radioisotopes have a range of uses in medicine and in industry;
- Radioactive isotopes can be used to date materials;
