CBSE Class 12 science: Radioactivity Videos | Radioactivity

• Half life Sums
• 55Cs124(Z=55,A=124) has a half life of 30.8s. (a) If we have 7.8 microgram initially, how many nuclei are presents? How many are present 2 min later? (b) What is the activity at this time? (c) After how much time will the activity drop to less than about 1 per second?
• how are we supposed to solve this question
  
• Carbon-14(C14) decays at a constant rate in such a way that it reduces to 50% in 5568 years. Find the age of an old wooden piece in which the carbon is only 25% of the original.
• Radioactive nuclei 
  
• Radioactive elements 
  
• Half-life period of a radioactive sample is 2 days. If the number of nuclei initially present is, find the number of nuclei present after 8 days?
• figure for 13.6 in chapter nuclei  
• The half life period of a radioactive substance is 30 days. What is the time for ¾ th of its original mass to disintegrate?
• How many α and β-partiles are emitted ₉₀Th²³² changes to ₈₂Pb²⁰⁸?

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