Do now! Can you continue the questions you started last lesson?
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Transcript of Do now! Can you continue the questions you started last lesson?
Do now!Can you
continue the questions you
started last lesson?
Today’s lesson
• Use the term half-life in simple calculations, including the use of information in tables or decay curves.
• Give and explain examples of practical applications of isotopes.
Do now!
Tomekitis
½ - life
• This is the time it takes half the nuclei to decay
half-life (t½)
Number of nuclei undecayed
timeA graph of the count rate against time will be the same shape
Different ½ - lives
• Different isotopes have different half-lives
• The ½-life could be a few milliseconds or 5000 million years!
half-life (t½)
Number of nuclei undecayed
time
Examples
• A sample of a radioactive isotope of half life 2 hours has a count rate of 30 000 counts per second. What will the3 count rate be after 8 hours?
Examples
Uses of radioactive isotopes
Used as Tracers
Used as Tracers
Used as Tracers
Killing microbes
Killing microbes
Thickness control
Thickness control
Smoke detection
Checking welds
Carbon dating
Summary sheet
“Can you………?”
Test!
• Wednesday 16th March (11X)
• Monday 21st March (11A)
Can you answer the questions on pages 261 and
265?