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Define radioactivity - Leaving Cert Chemistry - Question a - 2004
Question a
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 a - 2004
Step 1
Define radioactivity.
Answer
Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This decay can result in the release of particles or electromagnetic waves. Radioactive decay is a random process that can occur in different forms, including alpha, beta, and gamma decay.
Step 2
State two properties of beta (β) particles.
Answer
- Beta particles are high-energy, high-speed electrons (β-) or positrons (β+) emitted from a decaying atomic nucleus.
- Beta particles have moderate penetrating power; they can be stopped by materials such as plastic or a few millimeters of aluminum.
Step 3
Step 4
Explain how the carbon-14 isotope allows certain archaeological discoveries to be dated.
Answer
The carbon-14 isotope is useful for dating archaeological finds due to its presence in the atmosphere and subsequent absorption by living organisms. When an organism dies, it stops taking in carbon-14, and the isotope begins to decay at a known rate, with a half-life of approximately 5730 years. By measuring the remaining amount of carbon-14 in organic materials, scientists can estimate the time of death, providing a timeline for archaeological discoveries.