You change the independent variable in an experiment
Answer: The heat transfer by convection requires a solid-fluid interface, a temperature difference between the solid surface and the surrounding fluid and a motion of the fluid. The process of heat transfer by convection would occur when there is a movement of macro-particles of the fluid in space from a region of higher temperature to lower temperature.
Explanation:
Answer is: ammonia has a higher boiling point because it has stronger intermolecular forces.
Intermolecular forces<span> are the forces between </span><span>molecules. The stronger are intermolecular forces, the higher is boiling point of compound, because more energy is needed to break interaction between molecules.
</span>There are several types of intermolecular forces: hydrogen bonding, i<span>on-induced dipole forces, ion-dipole forces andvan der Waals forces.</span>