Which was a disagreement between the Catholic Church and the Eastern
Orthodox Church?

One of the many religious disagreements between the western Roman and eastern Byzantine branches of the church had to do with whether or not it was acceptable to use unleavened bread for the sacrament of communion. The west supported the practice, while the east did not.

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.

study of past cultures