Radioactivity

Question 1

Why does beta plus decay occur?

Answer 1

• Nucleus has too many protons for stability
  
  • nuclei are proton rich
  • are on the right side of stability band on NZ graph

Question 2

Why does beta minus decay occur?

Answer 2

• nucleus has too many neutrons for stability
  
  • nuclei are neutron rich
  • are on the left side of stability band on NZ graph

Question 3

How does beta decay occur?

Answer 3

• weak force causes a neutron to decay into a proton
  Or
• weak force initiates changes in nucleus that results in proton turning into neutron

Question 4

When does gamma decay occur?

Answer 4

• if a nucleus has surplus energy after an alpha or beta emission

Question 5

What is the pattern demonstrated by stable isotopes of elements?

Answer 5

• As number of protons in nuclei rises, ratio of neutron to proton also rises
• Only nuclei with proton numbers less than 20 are stable with same number of protons and neutrons

Question 6

Which nuclei are likely to decay through alpha decay?

Answer 6

• nuclei with proton number above 82