instruction:
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.
question:
Sentence1: Light source is an ultra-bright, unbreakable LED Bulb. 
Sentence2: LEDs convert electricity into light and heat energy.
answer:
LED


question:
Sentence1: if a neutral atom loses an electron then an atom with a negative charge will be formed. 
Sentence2: Ice crystals that are formed have a negative charge.
answer:
charge


question:
Sentence1: igneous rocks are formed from magma cooling. 
Sentence2: Basalt is formed from magma cooling.
answer:

cooling