You find a ring with a mass of 13.5g. You fill a graduated cylinder up with 10 mL of water and put the ring in the cylinders the water rises up to 15 mL. What is the substance

Idon't mean to be a smart alec, length of atoms' bonds is the simplest way to define it.

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.

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp