Chemistry help with half-lives?

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Chemistry help with half-lives?

The mass of cobalt-60 in a sample is found to have decreased from .800g to .200g in a period of 10.5 years. From this information, calculate the half-life of cobalt-60.

2007-10-08 12:34:56 · 2 answers · asked by Nohbdy 2 in Education & Reference ➔ Homework Help

2 answers

It has gone to 1/4 of the original. After one half-life it would be down to 1/2 and after two half-lives it would be down to 1/4. So 10.5 years is two half-lives and one half-life is 5.25 years, or 63 months.

2007-10-08 12:38:50 · answer #1 · answered by Howard H 7 · 0⤊ 0⤋

IT took 10.5 years to go to 1/4 of its original value.
That is 2 half lives.
So one half life is 5.25 years.

2007-10-08 19:38:38 · answer #2 · answered by ignoramus 7 · 0⤊ 0⤋