Radioactivity and Particles Flashcards
What are the 3 types of ionising radiation?
Alpha, beta and gamma radiation.
Describe the ionising power trend of each radiation:
-Alpha: strong
-Beta: medium
-Gamma: weak
Describe the penetrating power trend of each radiation:
-Alpha: weak
-Beta: medium
-Gamma: strong
What is the range in air of alpha radiation?
5-8 cm
What is the range in air of beta radiation?
500-1000 cm
What is the range in air of gamma radiation?
Virtually infinite.
What is alpha radiation stopped by?
Paper.
What is beta radiation stopped by?
Thin aluminium.
What is gamma radiation stopped by?
Thick lead sheet
What is alpha radiation?
Fast-moving particles that are thrown out of unstable nuclei when they decay.
What are alpha particles?
Helium nuclei.
What is the mass number of an alpha particle?
4
What is the relative charge of an alpha particle?
+2 (they carry 2 protons)
What are beta minus particles?
Very fast-moving electrons that are ejected by a decaying nucleus.
What does beta minus decay involve?
A neutron in the nucleus splitting into a proton and an electron to make the nucleus more stable. The proton remains in the nucleus and the electron is ejected at high speed as a beta minus particle.