Posted by **Gaby** on Tuesday, May 31, 2011 at 9:15pm.

A radium-226 sample initially contains 0.112mol. How much radium-226 is left in the sample after 6400 years. The half-life of radium-226 is 1600 years.

- chemistry -
**DrBob222**, Tuesday, May 31, 2011 at 10:29pm
long way.

k = 0.693/t_{1/2}

ln(No/N) = kt

No = 0.112 mol

N = unknown

k from above.

t = 6400 years.

shorter way.

0.112*(1/2^n)

0.112*(1/2^6400/1600)

0.112*(1/2^4) = N

- chemistry -
**Tanzeel Urooj**, Monday, April 22, 2013 at 3:30am
0.04 is the answer

- chemistry -
**Brandy**, Monday, July 28, 2014 at 4:10pm
The half-life of Radium -226 is 1600 years. How much Ra 226 remains in a 30.0 g sample after 6400 years?

## Answer this Question

## Related Questions

- Chem 3A - please help me with this chemistry problem. Half-Life A radium-226 ...
- Calculus - The half-life of Radium-226 is 1590 years. If a sample contains 100 ...
- nuclear chem - i need help solving this. Can you guys show me how it's done. ...
- physics - The half life period of radium is 1600 years.In how many years 1 gram ...
- Chemistry - Uranium-238 has half life of 4.51 * 10^9 years Uranium-234 has half ...
- Math - Exponential Decay - Radium decays exponentially. Its half-life is 1,690 ...
- Math - In 1976 a research hospital bought half a gram of radium for cancer ...
- Math - In 1976 a research hospital bought half a gram of radium for cancer ...
- Chemistry - Radium-223 has a half-life of 11.4 days.Approximately how long would...
- MATHS - please help me ...Experiments show that radium at rate proportional to ...

More Related Questions