A clause was added to the US Constitution that set the minimum number of states required to ratify the Constitution. A minimum of states had to ratify the US Constitution for it to go into effect.

A minimum of 9 states had to ratify the US Constitution for it to go into effect.

Explanation:

On September 28, Congress directed the state legislatures to call ratification conventions in each state. Article VII stipulated that nine states had to ratify the Constitution for it to go into effect

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.