Widow (wid´ō), n. a woman who has outlived her husband.

what does the symbol (´) indicate?

the syllable most emphasized
the o is a short vowel
the syllable least emphasized
the o is a long vowel

the syllable most emphasized

In the word widow, a stress is found in the first syllable which means that the first syllable of the word gains more emphasis compared to the other syllable. The stress sign does not talk whether the o is a long or short vowel. 

* current model - electrons move around the nucleus in an electron cloud

* J. J. Thomson's model - electrons are spread throughout the atom

Explanation: