mar 22, 1932 - James Chadwick calculates the mass of a nucleus.
Description:
In 1932 James Chadwick used math to calculate the mass of a neutral particle in the nucleus of an atom. We knew before this that there was something other than a proton in the nucleus that had great mass, but Chadwick was the first person to calculate it's weight and give it a name.Added to timeline:
Date:
mar 22, 1932
Now
~ 94 years ago