Question

The half-life of hydrogen-3 (tritium) is approximately 12 years. In how many years will half of a 20-gram sample decay by beta radiation to helium-3?

Answer 1

Answer: 12 years

Step-by-step explanation:

Answer 2

the easiest way to work this out is to think of the amount of decay as a percentage. so in 12 years its down to 50% another 12 years its down to 25%, another 12 years its 11.5 %.

for a 20 gram sample to decay by half will still be 12 years no matter how many grams one has.