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 Leaking Balloons
Name: Gina
Status: student
Age: 16
Location: N/A
Country: N/A
Date: 1999 


Question:
Could you please explain for me why a balloon filled with H2 or He has very little gas in it after 24 hours?


Replies:
The rubber walls of a balloon are porous on a very microscopic scale. H2 and He are very light molecules, and they move very fast. They can pass through the walls of a balloon faster than other gases. A rubber balloon filled with air will also go flat, but more slowly.

Mylar balloons are less porous; a Mylar balloon, even when filled with helium, will stay inflated for a much longer time.

Richard E. Barrans Jr., Ph.D.



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