Radioactivity Flashcards
What are beta particles?
Electrons
What are gamma rays?
High energy electromagnetic radiation
What effect does an electrical field have on an alpha particle?
Alpha particle shows a deviation towards the negative plate
What effect does an electrical field have on a beta particle?
Beta particles are attracted greatly to a positive plate
What effect does an electric field have on gamma rays?
No effect.
What is the penetrating power of alpha particles?
Least penetrating. Stopped by a piece of paper
What is the penetrating power of a beta particle?
Stopped by a thin sheet of metal( e.g. 0.5cm of lead)
What is the penetrating power of gamma rays?
Most penetrating. May take more than 2cm of lead to stop them
What happens when an atom emits an alpha particle?
Mass number decreases by four and atomic number decreases by two. Product is two places to the left in periodic table.
What happens when an element emits a beta particle?
The mass number is unchanged but the atomic number increases by 1. The new element is one place to the right in the periodic table. It can be said a neutron changes to a proton and electron
What happens when an atom emits gamma radiation?
Nothing.
What are alpha particles?
Clusters of 2 protons and 2 neutrons
Why is radioactivity a health hazard?
Radioactive emissions break chemical bonds in the cell molecules giving rise to changes in DNA which can cause mutations and the formation of cancer cells and or death.
What is half life?
The time taken for the radioactivity of a radioisotope to fall to half its initial value.
Give an example of the use of radioactivity in medicine.
Cobalt-60 in radiotherapy for the treatment of cancer. High energy gamma radiation is used to kill cancer cells.
Iodine-131 to trace uptake in thyroid glands.
