Ask A Scientist Chemistry Archive

Question:
Hello we are in lester elementary school. We have a question. If water 
gets radioactive when it is evaporated is its water vapor radioactive?
 
Answer 1:
Water doesn't get radioactive when it is evaporated.  Water in the
liquid state absorbs enough energy to go into the vapor state.  This
is called the heat of vaporization.  This process occurs when you
boil water.  Water also has a vapor pressure.  This essentially
relates how much water vapor is present above liquid water at a
particular temperature.  Radioactivity has to do with changing
the nucleus of atoms (like adding or subtracting neutrons), not
changing 
physical states of compounds (like going from liquid to gas).  Hope
that helps.
-Joe Schultz
 
Answer 2:
It seems to me the question being asked here, with some puntcuations
for clarity, is
 
If you have some water which has radioactivity associated with it,
and you boil the water, will the resultant water vapor be radioactive?
 
Ric


Answer 3:  I think Ric's right...
and the answer is yes, if the water is radioactive
then the vapor will be too.
 
prof topper

Answer 4:  Let's be careful about the question.  If the WATER is 
radioactive, the prof Topper is correct and the vapor will
also be re radioactive.  If something radioactive is dissolved in the
water, then the vapor itself will NOT be radioactive - unless the
radioactive substance is also evaporated.

Answer 5:  Absolutely!
 
topper