The Atom

Who were the main characters in the development of the atom?
Democritus, John Dalton, J.J. Thompson, Ernst Rutherford, Robert Millikan, Antonius van den Broek, and James Chadwick

Why were they vital to the development of the atom?
-Democritus belived every object was made up little things called atoms; depending on the shape of the atom, the object was a certain uncuttable particle called an atom.
-John Dalton proposed the existence of atoms; also, in 1803, John Dalton created the law of multiple proportions that states that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation.
-J.J. Thompson found that there must be positively charged particles which also must carry the mass of the atom. Dalton's model is now incorrect because atoms are divisible.
-Ernst Rutherford studied the deflection of alpha particles as they were targetedat thin gold foil sheets. The positive charge and mass of an atom were concentrated in the center and only made up a small fraction of the total volume. He named this concentrated center the nucleus.
-Robert Millikan proved Thomson's hypothesis that the mass of an electron is at least 1000 times smaller than the smallest atom.
-Antonius van den Broek suggested that the positive charge on atoms should be compared to their atomic numbers, not their atomic weights.
-James Chadwick proved that neutrons, neutral particles in the nucleus that made up approximately half the mass of an atom, did exist.



What made them different?
Each experiment performed by the scientists not only led to a discovery, it led to other discoveries through various scientists and scientific methods. All these men approached their experiments with different techniques; these techniques led them to countless discoveries of the atom, such as the proton, neutron, electron, atomic mass, atomic weight, and so on.



Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today.
As we go further and further into the past, we realize that these men did not have the technology that we have today. By not having the use of modern technology to their advantage, it is very easy to point out flaws in their experiments and theories. Although these men did not have the advantage we have today, we can conclude that they were very intellectual and thoughtful for their time period, leading them to new discoveries.


Why do we consider the atomic theory still a theory? What are the new developments?
The Atomic Theory still has yet to be proven, even though it has stood the test of time. New discoveries and add-ons have been made to this theory. Also, we have discovered a few flaws with this theory.




Why does it matter that we understand the structure of the atom?
Atoms are the basic building blocks off all matter. We must study the atom in order to understand their basic structure and why they exist. We are surrounded and even made up of atoms. By understanding the true nature of atoms, we can learn that they are more than just "random" particles.