The latent heat of melting is the amount of heat that must be added to 1 gram of a substance, at its melting point, to break the necessary bonds 
(The latent heat of melting; is; the amount of heat that must be added to 1 gram of a substance) (the amount of heat; must be added; to 1 gram of a substance)
The latent heat of melting the amount of heat
is must be added
the amount of heat that must be added to 1 gram of a substance
to 1 gram of a substance