Answer:
c. crystallization
Explanation:
The opposing process that occur in a solution in contact with undissolved solute are dissolution and crystallization.
In the dissolution process the solid substance coverts into liquid state and mixes with solution. Whereas in Crystallization the the chemical is converted from the liquid solution to solid crystal state.
Answer :
121.5 <span>
μCi
Explanation : We have Ce-141 half life given as 32.5 days so if the activity is 3.8 </span><span>μci after 162.5 days of time elapsed we have to find the initial activity.
We can use this formula;
</span>

3.8 /

=

((0.693 X 162.5 ) / 32.5) = 121.5
<span>
On solving we get, The initial activity as 121.5 </span>μci
I am pretty sure that <span>If I were asked to compare matter in solid, liquid, and gaseous states, the statement which would best defined a gas is </span>highest energy, highest molecular motion, and least dense packaging of molecules. I choose this one because it's not sensible to <span>heat CO2 (in case of safety) and in the last option the amount of energy is not satisfying.
Hope it helps!</span>
I believe the answer is "Bohr's model explains the chemical behavior of all atoms."
The first option is correct.