P6- Radioactivity Flashcards
What is an isotope
An atom with a different number of neutrons
What happens to unstable isotopes
They undergo radioactive decay
Define a radioactive material
A material that consists of unstable isotopes that can decay
What are the 3 types of radiation
- Alpha
- Beta
- Gamma
What is an alpha particle
A helium nucleus
- 2 protons
- 2 neutrons
What is the charge of an alpha particle
2+
(they have no electrons)
How is an alpha particle writen
4
He
2
How far can alpha particles travel
A few cm in air
What can absourb alpha radiation and why
A piece of paper.
Because alpha particles are relatively large.
How ionising is alpha radiation
Strongly ionising
- large 2+ charge
- can knock electrons off atoms easily
What is a beta particle
An electron
How do you write a beta particle
0
e
-1
How is beta radiation emitted
An atoms neutron decays into a proton and an electron, the electron is emitted at high speeds from the nucleus.
How ionising is beta radiation
Moderately ionising
- 1- weaker charge
- cannot knock electrons easily
How far can beta radiation travel
Several meters of air