All elements are made of "atoms", and an atom is made up from 3 basic particles: Electrons are particles with a negative charge :)
So other scientists can try the exact same experiment and see if they both got the same results.
After the NADPH molecules are formed, they bring pairs of the the molecules into the next part of photosynthesis. ... During this reaction, both the ATP and NADPH transform the carbon dioxide into carbohydrates. The carbon dioxide molecules come from the atmosphere and then enter the Calvin cycle