Definition: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
Input: Sentence1: When an atom or molecule is no longer neutral it is called an ion . 
Sentence2: if an atom loses an electron then it forms an ion.

ion