Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Surface Tension and Electrostatics 
Name: Shiva
Status: student
Age: N/A
Location: N/A
Country: N/A
Date: N/A
Question:
A razor blade is placed gently on a water surface. A charged body brought near the razor makes it move away.what is the difference between the bronze (which is used in the razor blade) and water? Is it related to the polarity of them?


Replies:
This is a very good example of surface tension at work. The razor blade is covered with a thin layer of hydrophobic lubricant, which is essentially invisible to the unaided eye. However, this thin layer of lubricant is able to support an electric charge so that the blade is repelled by a similarly charged body. The metallic composition of the blade itself has little effect. It's all on the surface. You can test this by first preparing a dilute solution of dish soap -- maybe about 10% soap in water. Then gently put a drop of the diluted soap on the surface of the water holding the razor blade. I think you will see the blade sink very quickly because the surface tension supporting the blade is weakened and can no longer hold the weight of the blade.

Vince Calder


Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory