In effect, it means that 7 grams of hydrogen combines with 1 gram of oxygen, or
6 grams of hydrogen combines with 1 gram of nitrogen. Thus, atom of oxygen is
seven times heavier than the atom of hydrogen, etc. Since these values are far from
the relative atomic masses that are known today, their use in the analyses of a larger
number of substances often led to contradictory conclusions. This would motivate
Karl Popper to reject the theory about atoms. However, it was this contradiction that
became the basis for the development of structural theory, the topic of the following
lecture.
There emerges also another question. If Dalton would publish his work by using
todays criteria instead the criteria of the beginning of 19th century, he would never
discover atoms! If the weights of elements that combine to form the compounds
would be measured with the high accuracy, then no integer numbers of weights
ratios would be observed. This is important fact about the nature of the scientific
method. The discoveries, as well as scientific laws and concepts, are the consequence of the historical state of the art in the moment or their discovery. Historical
circumstances are inseparable part of epistemology.
Dalton symbols of atoms and their combinations (the figure is copied from public
internet pages)
9 Atoms and Molecules
77
6 grams of hydrogen combines with 1 gram of nitrogen. Thus, atom of oxygen is
seven times heavier than the atom of hydrogen, etc. Since these values are far from
the relative atomic masses that are known today, their use in the analyses of a larger
number of substances often led to contradictory conclusions. This would motivate
Karl Popper to reject the theory about atoms. However, it was this contradiction that
became the basis for the development of structural theory, the topic of the following
lecture.
There emerges also another question. If Dalton would publish his work by using
todays criteria instead the criteria of the beginning of 19th century, he would never
discover atoms! If the weights of elements that combine to form the compounds
would be measured with the high accuracy, then no integer numbers of weights
ratios would be observed. This is important fact about the nature of the scientific
method. The discoveries, as well as scientific laws and concepts, are the consequence of the historical state of the art in the moment or their discovery. Historical
circumstances are inseparable part of epistemology.
Dalton symbols of atoms and their combinations (the figure is copied from public
internet pages)
9 Atoms and Molecules
77