Chapter 25 Radioactivity Flashcards
Describe what is meant by spontaneous random nature of radioactive decay of unstable nuclei
The decay occurs without external influence.
You cannot predict when/which each nucleus will decay next.
What is the decay constant?
The probability of a decay of a nucleus per unit time
What is the half life of a substance?
The average time taken for half of the substance to decay
What does activity mean?
The rate of decay of nuclei
Why does carbon dating not work for samples greater than 10⁵ years old?
The activity is so low that it can’t be differentiated from background radiation.
Explain the technique of radioactive carbon dating?
Living animals absorb C-14
Once dead plants take in no more C-14
The activity of the nuclei in a dead and an alive compound are compared
Use equation A=A₀e⁻λt
