Answer:
>
> 
Explanation:
The order of boiling point depends upon the type of interactions present between the molecules.
Potassium fluoride (KF) is an ionic compound and the opposite ions are held together by strong electrostatic forces.
is a covalent compound and the molecules are held together by weak van der Waals' forces.
Formaldehyde is a polar compound due to presence of polar carbonyl group. Hence dipole-dipole force is present between formaldehyde molecules.
Thus the decreasing order of boiling point is:
>
> 
1000 to the power 4 not so good at math but
An increase in temperature increases the average kinetic energy of molecules.
When the temperature of a molecule increases, the molecule starts to move at a faster rate. The faster a molecule moves, the more kinetic energy it has.
<span>No uses regarding the human body; it's a noble gas and does not react with anything.</span>