Section 3 - Radioactivity & Astronomy

Question 1

Alpha VS Beta

Answer 1

ALPHA
• particle (not a wave)
• made up of 4 particles
• Helium nucleus
• positive charge
• when emitted by a nucleus, atomic number goes down by 2
• mass number goes up by 4

BETA
• particle (not a wave)
• made up of 1 particle
• fast-moving electrons
• when emitted by a nucleus, atomic number goes up by 1
• mass number stays same

Question 2

Explain the difference between nuclear fusion & nuclear fission

Answer 2

NUCLEAR FUSION
• two small nuclei join to make a bigger one —> for this to happen, the two nuclei have to get very close to each other
• very high temperatures & pressures are needed
• provides the energy that makes stars shine

NUCLEAR FISSION
• large unstable nuclei split up
• one reaction can cause more to happen, in a chain reaction
• doesn’t need high temperatures and pressures
• produces radioactive waste materials

Question 3

Elastic potential energy equation

Answer 3

0.5 x spring constant x extension squared

Question 4

GPE

Answer 4

mass x gravitational field strength x height