London dispersion forces are weak Vanderwal forces that exists between
all molecules.
Dipole-dipole forces operates between polar molecules because of the attraction between slightly developed opposite charges.
Hydrogen-bonding is the strongest dipole-dipole interaction because of the largest electronegativity difference between hydrogen atom and the most electronegative atoms like F,O,N.
London forces are common to all molecules, it results from momentary shifts in electron distribution in molecules. When molecules possess a permanent dipole, dipole-dipole interaction is the dominant intermolecular force. However, for compounds in which hydrogen is bonded to highly electronegative element, hydrogen bonding is important.
<span>When a chemical reaction occurs and the thermometer in the container records a drop in temperature t</span>he reaction is exothermic because heat was released by the reaction.
<span>B. The reaction is exothermic because heat was released by the reaction. is your answer.
