radioactivity

Question 1

what is a chain reaction

Answer 1

• a chain reaction occurs when a (an incidental) neutron gets absorbed by a large unstable nucleus (e.g. uranium - 235)
• this then splits into two smaller daughter nuclei and a few neutrons
• the neutrons get absorbed by other unstable nuclei which causes them to split into daughter nuclei and release more neutrons
• this is called a chain reaction

Question 2

what is the unit for radioactivity

Answer 2

bequerels (Bq)