Radioactivity Flashcards
Describe how protons, neutrons and electrons are arranged in an atom.
The protons and neutrons make up a central nucleus. The electrons orbit the nucleus.
State the could cause an electron to move to a higher energy level.
The electron has absorbed electromagnetic radiation.
Name and describe the atomic model that Rutherford’s nuclear model replaced.
The plum pudding model. Spheres of positive charge, electrons stuck in them.
What are isotopes?
Atoms who’s nucleus have the same number of protons/ same element but a different number of neutrons.
What unit is radioactivity measured in.
Becquerels / Bq
What is meant by background radiation.
Low-level radiation that is around us all the time.
Name 2 sources of background radiation.
Rocks and food.
State what is meant by half-life
The time taken for half of the radioactive nuclei to decay.
State what is meant by ‘irradiation’ and ‘contamination’
Irradiation is when an object is exposed to radiation. Contamination is when unwanted radioactive particles get onto or into an object.
Give two ways that a scientist can protect themselves against exposure when handling radioactive sources.
Storing sources in a lead-lined box. Using tongs.
