Please help, it's for CHEMISTRY Gas Law Calculation

Answer two atoms of oxygen;

Ibelieve it's temperature! i'm not 100% sure.

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.