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 Atomic Size Limits
Name:  Daniel
Status:  educator
Age:  30s
Location: N/A
Country: N/A
Date: 2000-2001

Is there a theoretical upper limit on the size of an atom, and how stable are extremely large atoms predicted to be?

Dear Daniel,

I'm not aware of any theoretical limit.

I'm not sure how large you are asking about, but stability is a very difficult thing to predict for huge atoms. Relativistic effects become important for the core electrons (especially) as the atomic number increases, and there is no completely covariant quantum mechanics yet that can be used to do such calculations (at least not to my knowledge!).

Best regards,
Prof. Topper

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 (, or at Argonne's Educational Programs

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

Argonne National Laboratory