Atomic Theory is one of the theories of chemistry and physics. This theory is also known as a very famous theory that is related to Dalton, who fixed one of the atomic theories. 80 years later, one of the physicists and chemists found another theory that related to Dalton's, in which Niels Bohr made a new version of the atomic theory. There are many things related to atomic objects that were also developed because of these two scientists. Now I will talk about atomic theory first.

In the early 1800s, John Dalton was the first to form the professional atomic theory. For Dalton’s Theory, it explains the matter of particles called atoms. Furthermore, atoms are so small that they can’t be seen with the naked eye. In his study, there are also explanations of the system of chemical philosophy that relates to his law of multiple proportions. There are three examples here.

The first example is named “tin oxides”. They are known as primarily two types. One of them is protoxide of tin for eight-ninths of tin and one-ninths of oxygen. And another one of them is the deutoxide of tin that is 13.5% oxygen. And these two are also different colors. Protoxide of tin is a grey powder, but the deutoxide of tin is a white powder that can be either a monoxide or a dioxide.

For the second example, we will now go to iron oxides. Iron oxides are also identified into two groups. One of them, the protoxide of iron, is known as 80% iron and 20% oxygen. The other form of iron oxide is the intermediate or red oxide of iron that contains 70% iron and 30% oxygen. Furthermore, there are also differences in the powder’s color. The first one is black and the second one is red.

For the last example, there are nitrogen oxides which have three oxides of nitrogen. First one is nitrous oxide, the second one is nitrous gas, and the last one is nitric acid. And for its contents, the first one contained about 65% nitrogen and the rest of its components are oxygen. The next one contains 45% of nitrogen. The last one contained 30% nitrogen and the other 70% are all oxygens. But other than the above two, it is only for gas. This is because it only contains nitrogen and oxygen. Also, Dalton made the elementary atoms and compound atoms in these examples. This is known as a binary compound, which is made of 2 of them.

For Bohr’s model, there are 2 layers in it. But there, if the electricity disturbs one layer, then its neutron ion goes out. But if the out of the electric came, the neutron ion goes in again. It was formed in 1912, but his model was not perfect at all. This is because there are none about multielectron atoms. And it became worse. However, in 1916, one scientist, Arnold Sommerfeld, added something that orbits Bohr’s model, and now it has become perfect.