P4 Flashcards
Radioactive Decay
Some atomic nuclei are unstable. The nucleus gives out radiation
as it changes to become more stable
What is the activity?
Activity is the rate at which a source of unstable nuclei decays
What is activity measured in?
Becquerel (Bq)
What is the Count - Rate?
The number of decays recorded each second by a
detector (eg Geiger-Muller tube)
How can nuclear radiation be emitted?
- Alpha Particle
- Beta Particle
- Gamma Ray
What does an Alpha Particle consist of?
Consists of two neutrons and two protons, it is the same as a helium nucleus
What does a Beta Particle consist of?
Electron
What is a Gamma Ray?
Electromagnetic radiation
What is the air range of a Beta Particle?
1 metre
What is the air range of a Gamma Ray?
Hundreds of metres
What is the air range of an Alpha Particle?
8 centimetres
What is an Alpha particle stopped by?
Skin or Paper
What is a Gamma-ray stopped by?
Thick Lead
What is a Beta particle stopped by?
Thin Aluminium
How many atoms can 1 Alpha Particle Ionise?
10,000; it has a high charge, cant travel far