Posted by **Nancy ** on Thursday, August 2, 2012 at 1:18pm.

Find the number of disintegrations per minute emitted by 1.1 mol of 232-Th in 1 min. The half-life of 232-Th is 1.4 x 1010 year

I was able to do this with the following technique:

1.1 x 6.022 x10^23 =6.62x10^23

1.4x10^10=7.358x10^15 minutes

I think then it is 6.62x10^23 x 7.358x10^15

But I want to learn how to do this problem using the formulas below instead of the .693/half life.

There are the following formulas:

starting amount) x (1/2)number of half-lives = ending amount (sometimes remaining rather than ending is used)

(1/2)number of half-lives is the decimal fraction which remains (1.000 is the original starting amount, 0.500 at the end of one half-life, 0.250 at the end of two, 0.125 at the end of three, etc.)

number of half-lives that have occurred can be expressed as (total time elasped ÷ length of half-life)

## Answer This Question

## Related Questions

- Chemistry - The half-life of Th-232 is 1.4E10. Find the number of ...
- Chemistry - The half-life of 232Th is 1.4 * 10^10. Find the number of ...
- Chemistry 11 - A hydrate of zinc chlorate, Zn(ClO3)2 .xH2O(s) contains 21.5% ...
- A.P. Chemistry - Thorium-232 undergoes alpha decay and has a half-life of 1.4 * ...
- chemistry - What would be the mass ratio of Pb-208/Th-232 in a meteorite that is...
- CHEMISTRY - Calculate the ƒ¢H‹ rxn for the following reaction. ƒ¢H‹ f [H2S(g...
- physics - calculate the number of kilocalories needed to climb 232 stair steps (...
- Chemistry - The cloth shroud from around a mummy is found to have a carbon-14 ...
- Chemistry - Chromium is electroplated from an aqueous solution containing H2SO4 ...
- Chemistry - An archeological artifact was subjected to radiocarbon dating. The ...

More Related Questions