Science Questions with Surprising Answers
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Dr. Christopher S. Baird

Why don't objects fuse to my finger when I touch them?

Category: Chemistry      Published: December 20, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and Associate Professor of Physics at West Texas A&M University

child with dirty hands
This child has definitely bonded with her environment. There is always bonding involved when you touch an object, but the effects are often too weak to notice. Public Domain Image, source: Christopher S. Baird.

Objects always fuse to your finger when you touch them. You often don't notice this for two reasons: 1) Your finger is stronger than the object you are touching. When you pull away, you rip atoms off the object and these atoms remain fused to your finger as a microscopic residue. 2) Your finger is stronger than the bonds fusing you to the object. When you pull away, you simply break the bonds holding you to the object. If you notice this at all, you experience it as a sticky feeling when you pull your finger off of a substance.

At the atomic level, the fusing of your finger occurs because of chemical bonding. There are several different types of chemical bonds:

Note that bonding occurs at the surface of the objects that you are touching. Because of this fact, the act of bonding to every object that you touch does not really change who you are. It just makes your hands dirty, takes off some dead skin cells, or gives you a (sometimes imperceptible) sticky feeling when you pull away. Additionally, every time you experience friction, you are feeling the bonding between you and the rubbing surface slowing you down.

Examples of objects and substances that will bond strongly enough to your hands for you to notice include:

Topics: Van der Waals, bond, bonds, chemical bond, covalent, electromagnetism, interaction, ionic, sticky