# math

posted by
**Anonymous** on
.

Suppose that drilling into what was once a lake bottom produces a piece of

wood which, according to its mass, would have contained 5 nanograms (5 billionths of a gram) of carbon-14 when the wood was alive. Use the fact that this radioactive carbon decays continuously at a rate of about 1.2% per century to analyze the sample.

a. How much of that carbon-14 would be expected to remain 1 century later?

2 centuries later? x centuries later?