What is the half-life of a sample where the activity drops from 1,200 Bq down to 300 Bq in 10 days? Learn about and revise nuclear radiation, radioactive decay and half-life with GCSE...

The definition of half-life is the time taken for the count rate from a sample to decrease to half the initial value. If we use a radiation detector, such as a Geiger-Muller tube, we can measure the radiation being emitted from a a sample and calculate the radioactive half life from the results.

2024年12月10日 · Revision notes on Half-Life for the AQA GCSE Physics syllabus, written by the Physics experts at Save My Exams.

The half-life of a radioactive isotope is the time it takes for the number of nuclei of the isotope in a sample to halve. The time it takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level.

2010年4月2日 · Determine the half-life of this material. Step 1: Draw lines on the graph to determine the time it takes for technetium to drop to half of its original activity. Step 2: Read the half-life from the graph. A particular radioactive sample contains 2 million un-decayed atoms. After a year, there are only 500 000 atoms left un-decayed.

Scientists cannot tell when a particular nucleus will decay but they can use statistical methods to tell when half the unstable nuclei in a sample will have decayed. This is called the half-life .

Half - life is a measure of the time taken for the unstable nuclei to change into stable nuclei. Different substances do this at different rates. Some do it very quickly and half of the unstable nuclei decay in less than one second. For example, lithium - 8 has a half - …

What is the half life? Everything you need to know about Half Lives for the GCSE Physics (Combined) Edexcel exam, totally free, with assessment questions, text & videos.

Understanding half-life helps us manage both deliberate uses of radiation (like medical imaging or treatments) and accidental exposures (like nuclear power plant accidents), by enabling predictions of how radiation levels will change over time.

Carbon-14 is a radioactive isotope that occurs naturally. Scientists use carbon-14 to help find the age of old pieces of wood. This technique is called carbon dating. It uses the idea of half-life. Which of these describes half-life? Put a cross ( ) in the box next to your answer. the time it takes for half of the undecayed nuclei to decay.