The atomic mass of an element is the weighted average value of the masses.

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.

there is often only a small difference between what is legal and what is ethical when working with competitive intelligence..

the economic difference between the three colonial regions. shipbuilding, whaling, fishing, and trapping where also main factors to the economy. the southern regional colonies economy was based on sugarcane, rice, cotton, tobacco, and indigo.