A 350.0 gram sample of an unknown substance is heated by 256.2 calories of energy and changes temperature from 26.5 degrees celsius to 28.9 degrees celsius. What is the specific heat of this unknown in calories per gram degree celsius?​

Polymerization reaction

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

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