Radioactive decay Flashcards
What elements undergo alpha decay?
Elements heavier than lead as they are very unstable
What is alpha decay?
One alpha particle is lost: 2 protons and 2 neutrons (helium),
Atomic number decreases by 2, mass decreases by 4
thus the element is changed
What elements undergo beta decay?
Nuclei with too many neutrons
What is beta decay?
A neutron gets converted into a proton and one beta particle (a highly energised electron) being emitted
Atomic number increases by 1
Atomic mass stays the same
What elements undergo gamma decay?
Parent nucleus in a high energy or excited state
Can occur simultaneously with other forms of decay
What is gamma decay?
Gamma radiation is expelled from the nucleus
Gamma radiation has no mass so no change to actual element
What can alpha radiation be stopped by?
Paper
What can gamma radiation be stopped by?
Lead
What can beta radiation be stopped by?
Aluminium
What is an element’s half life
The time it takes for half the starting material to decay
What can half life be used for?
You can predict how much original sample will remain after a period of time
Can be used to perform radioactive dating
Is radioactive decay linear?
No, it is exponential
