Heated is a verb (past tense and past participle of heat). Example: Heat the food before serving.
Past participles can be adjectives--a heatedargument.
The hottest part of the oven when baking is typically the top heating element or the bottom heating element, depending on the oven design.
The hottest part of the oven used for baking is typically the top heating element or the top rack closest to the heating element.
"Wavelength" is a noun.
"Sunshine" is a noun.
An adjective
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "breezy" is an adjective.
The part of speech for "buried" is a verb.
The part of speech for "indefinite" is an adjective.