At STP (standard temperature and pressure), one mole of a gas occupies 22.41 liters of volume. Avogadro's number (6.022*10^23) is the number of molecules per mole of a substance, or one mole of anything really. This means there are 6.022*10^23 molecules of any gas with a volume of 22.41 L at STP.
It is B. What I found is when water freezes it's entropy decrease. If water freezing that means the temperature is decreasing and that is B.
Alpha decay involves the loss of an alpha particle, aka a helium nucleus. This results in the mass number of the original element decreasing by 4 and the atomic number decreasing by 2. Assuming 23942u is uranium (92), the resulting element's atomic number is 90, making it thorium.
