They go through radioactive decay because when atoms are unstable by going through it they are emitting radiation in natural process and they gain stability by losing energy.
Answer:
Explanation: Does any of this look right? To be honest I just looked it up.
Answer:
The pressure is higher than the atmospheric one, therefore the temperature is less.
Explanation:
When it is closed permanently, the pressure of the pot inside it increases, generating that the atoms and particles of the water are closer together, increasing their kinetic energy, if intermolecular friction and therefore the boiling point is lower, because the water reaches a boil or boil at a lower temperature.
If they're different sizes and densities, you are able to separate the substances.