system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it that when 2 parts Hydrogen (a highly flammable gas) is combined with 1 part Oxygen (a gas that feeds fire) it creates a liquid that is used to put out fire?
gpt
Because water and oxygen are very different chemicals. Changes as small as one electron can mean huge differences between molecules and individual elements. And the difference between water and oxygen is way more than one electron. That’s why their properties are very different. 

Look the difference between oxygen we breathe O2 and dangerous Ozone O3. Little changes in chemistry can mean big differences in the properties of a substance.