Two compounds have the same formulas but are geometrically different. how are these two compounds related? they are alkenes. they are alkanes. they are isomers. they are alcohols.

Well to my expert knowledge and my exquisite calculations i think the the negative ion # 412 is the key to sucess

The answer will be c

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.