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Define radioactivity - Leaving Cert Chemistry - Question 11 - 2004
Question 11
Define radioactivity. State two properties of beta (β) particles. Write an equation for the nuclear reaction involved in the beta decay of ¹⁴C (carbon-14). Explai... show full transcript
Worked Solution & Example Answer:Define radioactivity - Leaving Cert Chemistry - Question 11 - 2004
Step 1
Step 2
State two properties of beta (β) particles.
Answer
- Beta (β) particles have a negative charge and are significantly smaller and faster compared to alpha particles, traveling at a high speed.
- They are more penetrating than alpha particles, capable of passing through materials that stop alpha radiation, typically penetrating about 2-5 mm of aluminum.
Step 3
Write an equation for the nuclear reaction involved in the beta decay of ¹⁴C (carbon-14).
Answer
The nuclear reaction involved in the beta decay of carbon-14 can be represented as:
ightarrow ^{14}_{7} ext{N} + e^- + ar{ u}$$ Here, carbon-14 (C) decays into nitrogen-14 (N), emitting a beta particle (electron) and an antineutrino (ν).Step 4
Explain how the carbon-14 isotope allows certain archaeological discoveries to be dated.
Answer
Carbon-14 dating relies on the constant ratio of carbon-12 to carbon-14 in living organisms, which remains relatively stable while the organism is alive. After death, carbon-14 begins to decay at a known rate, with a half-life of about 5,730 years. By measuring the remaining amount of carbon-14 in a sample and comparing it to the original ratio, scientists can determine the time that has elapsed since the organism's death, thus dating archaeological discoveries.