Particles And Radiation Flashcards
What is ionising Radiation?
Any form of radiation that interacts with matter, resulting in ionisation of that matter.
What is ionisation?
The formation of charged particles from neutral molecules or atoms by adding or removing electrons.
What are the types of radiation?
-Alpha
-Beta
-Gamma
What is alpha radiation and describe their properties?
-are helium nuclei meaning that they consist of two protons and two neutrons (which give them a positive charge).
-are relatively large compared to beta particles.
-Alpha particles do not penetrate through materials very far. They can travel just 1-2cm in air and can be absorbed by a sheet of paper.
What is a beta particle and describe its properties?
-is a fast moving electron
-are less ionising than alpha particles and can penetrate materials a moderate amount.
What are gamma particles and describe its properties?
-is a form EM radiation.
-weakly ionising but with high penetrating power
-can be absorbed by thick sheets of lead or several metres of concrete.
What is half life?
the time taken for half the unstable nuclei in a sample to decay.
what is radioactive decay?
is detected and measured by using a Geiger-Muller tube and counter.
How does radiation interact with matter?
Radiation interacts with matter in two ways: ionisation and excitation.
When does excitation occur?
Excitation occurs when radiation transfers energy to atoms or molecules.Excitation involves moving an electron to a higher energy level.
What are the uses in radioactive tracers?
*can be used to detect the presence of materials such as dust,cellulose fibers,glass fragments as these all absorb radioactive tracers from solution.
what is radiocarbon dating?
Measures the age of any object that contains organic material.This includes dead organisms.
