# 4n series

1. Sep 17, 2011

### crees503

Why is the Thorium decay series called 4n? I've looked it up but the explanation isn't clear

2. Sep 17, 2011

### mathman

Thorium-232 and all its daughter nuclides have atomic mass numbers (number of protons plus number of neutrons) which are multiples of 4, i.e. 4n, where n is an integer.

Last edited: Sep 17, 2011