Half Life Calculations Phosphorous32 has a half life

Half Life Calculations Phosphorous-32 has a half life of 14. 7 days

HALF LIFE CALCULATIONS: Half –Life Fraction of Parent % Daughter % 0 1/1 100 0 1 1/2 50 50 2 1/4 25 75 3 1/8 12. 5 87. 5 4 1/16 6. 25 93. 75 5 1/32 3. 125 96. 875

EXAMPLE • V 1. What is the original mass of the parent isotope? 2. What is the length of time in years for ½ of the Co-60 to decay? 3. How much time has passed after 3 half lives? 4. What percentage is left after 3 half lives? 5. If 50% of Co-60 remains at 1 half life, how much in (grams)

EXAMPLES 1. YOU HAVE 400 ATOMS OF A RADIOISOTOPE WITH A HALF-LIFE OF 5 MINUTES. HOW MUCH WILL BE LEFT AFTER 30 MINUTES? 2. SUPPOSE YOU HAVE A 100 MG SAMPLE OF AU-191, WHICH HAS A HALF-LIFE OF 3. 4 HOURS. HOW MUCH WILL REMAIN AFTER 10. 2 HOURS? 3. COBALT-60 IS A RADIOACTIVE ISOTOPE USED IN CANCER TREATMENT. CO 60 HAS A HALF-LIFE OF 5 YEARS. IF A HOSPITAL STARTS WITH A 1000 MG SUPPLY, HOW MANY MG WILL NEED TO BE PURCHASED AFTER 10 YEARS TO REPLENISH THE ORIGINAL SUPPLY? 4. A RADIOISOTOPE HAS A HALF-LIFE OF 1 HOUR. IF YOU BEGAN WITH A 100 G SAMPLE OF THE ELEMENT AT NOON, HOW MUCH REMAINS AT 3 PM? AT 6 PM? AT 10 PM?

HALF LIFE EXAMPLES • THORIUM-230 DECAYS WITH A HALF LIFE OF 80, 000 YEARS. IF AN INITIAL SAMPLE HAS A MASS OF 10. 00 GRAMS, HOW MUCH WILL REMAIN AFTER 320, 000 YEARS? • SOLUTION AMOUNT 10 GRAMS TIME ___ DAYS (YEARS)

HALF LIFE EXAMPLES • RADON-222 DECAYS WITH A HALF-LIFE OF 3. 82 DAYS. IF AN INITIAL SAMPLE OF THE ELEMENT CONTAINS 1000 ATOMS, HOW LONG WILL IT TAKE FOR THE SAMPLE TO DECAY DOWN TO 125 ATOMS? YOUR TIME MUST ALWAYS START AT 0 DAYS! • SOLUTION AMOUNT TIME 1000 ATOMS 0 DAYS

HALF LIFE EXAMPLES • AN INITIAL SAMPLE OF ZINC-61 CONTAINS 215 GRAMS. AFTER 976 DAYS, THE SAMPLE SIZE HAS REDUCED TO 13. 4375 GRAMS. WHAT IS THE HALF-LIFE OF ZINC-61 ATOMS? • SOLUTION AMOUNT 215 GRAMS TIME 0 DAYS