Carbon Trust Standard

The Carbon Trust Standard is the world s leading independent certification of an organization s impact with respect to the three primary constituents of environmental sustainability ... 

Awarded to recognize best practices and real achievements in reduction, the Carbon Trust Standard helps organizations to measure, manage, and reduce their environmental impact, whilst improving their resource management and operational sustainability (Carbontrust). 

Atomic mass units are based on something called the Carbon 12 scale, a worldwide standard that s been adopted for atomic weights. By international agreement, a carbon atom that contains 6 protons and 6 neutrons has an atomic weight of exactly 12 amu, so 1 amu is Yu of this carbon atom. I know, what do carbon atoms and the number 12 have to do with anything Just trust me. Because the mass in grams of protons and neutrons are almost exactly the same, both protons and neutrons are said to have a mass of 1 amu. Notice that the mass of an electron is much smaller than that of either a proton or neutron. It takes almost 2,000 electrons to equal the mass of a single proton. 

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