What are all the products of a hydrocarbon combustion reaction? A. Carbon dioxide, water vapor, and heat

B. Oxygen, a carbon-based molecule, and heat

C. Hydrogen, carbon, and oxygen

D. Carbon dioxide, oxygen, and water

That depends. cause the owl finished it in one lick

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.