Attraction of water droplet to my finger?

  • Context: Undergrad 
  • Thread starter Thread starter pivoxa15
  • Start date Start date
  • Tags Tags
    Attraction Water
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 4K views
pivoxa15
Messages
2,250
Reaction score
1
After a rain, when there are tiny water droplets hanging down from places, I can put my dry finger near one of the droplets and if my finger is close enough to the droplet, it will jump onto my finger. Just like a metal jumping onto a magnet.

What physical explanation could be given here? Is it simply the negative ends of all the water molecules in the droplet attracted to my positively induced finger?
 
Physics news on Phys.org
i think you hit it, negative polarity on the oxygen end of water attracts to your positively charged finger.

if you're finger was slightly wet though it would have been due partly to the polarity of the molecules and partly due to hydrogen bonding
 
rctrackstar2007 said:
i think you hit it, negative polarity on the oxygen end of water attracts to your positively charged finger.

if you're finger was slightly wet though it would have been due partly to the polarity of the molecules and partly due to hydrogen bonding

This is indeed a good point, sweat contains not only the polar H2O water molecule, but also ionic compounds, which could contribute to the effect. If your finger is damp / sweaty you will have both cohesion and adhesion.

~H