How many syllables does the word reaction have?

Answer 1

It has 3 syllables. Almost any dictionary will give you the syllable breakdown of a word. The main, bold word is often divided by dots which indicate the syllable breaks. In the case of reaction, it's re-ac-tion. If you are using a dictionary which also gives pronunciation, you'll find the phonetic spelling (the pronunciation code) within the slashes \word\.