Democritus and John Dalton

Hi everyone, welcome back to Chem Help ASAP. We are marching through the history of the atom and our understanding of atomic structure. We are actually gonna start back in ancient Greece with a man named Democritus who proposed that matter was actually not continuous, but was composed of tiny particles called atoms. Well, unfortunately for Democritus and the philosophers that agreed with him, the world just shelved his ideas for thousands of years, and we really don't get the ball rolling until we hit John Dalton in the 1800s. In 1808, John Dalton published his new system of chemical philosophy, and this really got the ball rolling again and changed the way we thought about atoms. So in this publication, he proposed four main tenets of the nature of matter. Main idea number one, just like we said before, matter is made up of tiny particles called atoms, and these are indestructible. Idea number two was that all atoms of a given element are identical. All carbon atoms are identical. All hydrogen atoms are identical. All sodium atoms are identical. However, each element's atoms differ from each other in size and mass. Main point number three is that atoms combine in fixed ratios to form different compounds, and if you're forming the same compound, that ratio will be consistent. It will not change. Water is always gonna be two hydrogens to one oxygen. If you have two hydrogens to two oxygens, you've actually formed a different compound called hydrogen peroxide. Main idea number four was that in the chemical reaction, atoms are rearranged. However, they are not created or destroyed. They are just gonna be bonded in different ways. John Dalton, obviously really smart guy, sparked the start of more research into the nature of the atom, and in our next video, we will start to talk about other scientists that took what Dalton started and carried the ball farther along and really started unraveling the mystery of what an atom is. Thanks so much for watching.