Democritus developed the idea of an atom and how the universe is made up of these tiny indestructible atoms..
Aristotle had a theory that there were only 5 elements, and those elements make up everything. Either by themselves or combined. Those elements were Air, Earth, water, fire, and aether.
Columbus arrives in Americas
1775 - 1783
American Revolutionary war
American Civil War
1861 - 1865
In the United States, the North vs the South fought because of the enslavement of balck people
Neils Bohr created the first accurate model of the atom. He said that the nucleus was positively charged and the negatively charged electrons circled around the outside of the nucleus. He discovered that electrons travel in separate orbits. This model is still used to this day, which is why he had such a huge contribution to the model of an atom.
World War 1
1914 - 1918
Discovered Neutrons and that they have a neutral charge, meaning they have no charge. This discovery allowed atomic bombs to be made which had a huge impact on World War 2.
World War 2
1939 - 1945
When the United States dropped the first-ever atomic bomb on the Japanese, in Hiroshima.