Science-forums who is credited with formulating the doctrine of uniformitarianism?

The correct answer is James Hutton

He explained that new scientific discoveries are in direct relations to previous scientific discoveries through causality and that the scientific laws are invariable through time, meaning that the laws of science have always been the same since the beginning of  time, and will remain so in the future.

An element's mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number.

Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.