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 of Water 
Name: Eva Karen McInnis
Status: student
Age: 10
Location: N/A
Country: N/A
Date: 1999
Question:
Why does a dome form on a coin when you pipette water on it drop by drop?

Replies:
Water is a polar molecule-that is it has a negatively charged end and a positively charged end. The negative end of one water is attracted to the positive end of another and they stick together tightly. So when you drop water on a coin the molecules of water in the new drop stick to the water droplets in the old drops until gravity overcomes the electric forces. How many drops can YOU pile on a coin before it spills over?

K. VanHoeck


Click here to return to the General Topics 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