English seems to be a mix of languages, the same structure may produce different sounds. So if you never heard the word you cannot be sure how it is pronounced:

Example:

STEAK

SPEAK

The only difference is the second consonant, the same happened to me the first time I saw the word I pronounced it with the /ea/ as in speak. Sneak is another example that sounds like speak.

With accentuation is similar:

"Component" I've heard that word pronounced with emphasis in the first syllable "Com" and also with emphasis in the second syllable "po". But have not heard that same duality in other very similar words in structure like "Impotent", "Exposen", etc.

That is weird to me, my native language is Spanish and we have rules on pronunciation and accentuation. If you know the rules you know exactly how to pronounce the word even if you never heard it before (with very few exceptions).