What does it mean when someone is called a "benedict arnold"

It means they are a traitor.

Benedict Arnold was famous for being a traitor.

They are traitorous.

Explanation:

Benedict Arnold was a British spy who spied on General George Washington, and gave American war secrets to the British during the American Revolution.

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.

mount st. helens in washington erupts, causing a massive avalanche and killing 57 people on this day in 1980. ash from the volcanic eruption fell as far away as minnesota. seismic activity at mount st. helens, which is 96 miles south of seattle, began on march 16.