system
Given the following post, respond as if you're commenting on Reddit:
human
Why does lithium react so violently with water?

I've seen somebody put lithium in water, obviously it started crackling and creating sparks but I wanted to know why.
gpt
Atoms and molecules are always trying to find their way to their most stable state.  In the case of Lithium, it has an extra valence electron compared to the noble gases (with their full outer shells), and it'd prefer not to have that one, so it donates it readily, forming an ion with +1 charge.  That ion, however, wants to be neutralized by something with a -1 charge, which it can pull off by pulling an OH- from the water (which is plentifully surrounding it while immersed in water).  The hydrogen is then free to become whatever it wants to be!  But in this case, the reactions gave off a lot of heat, and the hydrogen then finds the most stable thing it can become again is water - by reacting with the oxygen in the air.  So while it's a fiery, messy (and possibly explosive - wear your goggles kiddies) reaction, in the end state, all the atoms and molecules have, essentially, become what they most wanted to be - neutralized and stable.