8. The mass of the atom sodium-23 is 22.9898 amu. (a) Calculate its binding energy per atom in millions of electron volts.
(b) Calculate its binding energy per nucleon.

And a) oxygen i believe

Ais your answer to this

The state or quality of being humid.a quantity representing the amount of water vapor in the atmosphere or a gas.

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.