Timeline of the Atom by

2500 years ago

declanarcand — 2024-02-05 18:02:06 UTC

Greek philosopher Leucippus and Democritus made the theory that matter is composed of tiny particles called "A tomos" and each object had its only particle. for example iron was made up. with iron particles.

Late 1800's

declanarcand — 2024-02-05 18:12:17 UTC

Physicist J.J. Thompson used discharged cathode ray tubes to show that there is both positive and negative charges to matter called "electrons" that were 1000 times smaller than a hydrogen atoms. He also thought that electrons were randomly distributed throughout the atom, he compared it to plum pudding.

1909

declanarcand — 2024-02-05 18:27:22 UTC

Physicist Earnest Rutherford shot positively charged alpha particles at a thin piece of gold foil. some of the particles went straight through the gold foil but some deflected at large angles. He concluded that all the positively charged particles were in one place at the centre of the atom called a "nucleus". He also found that most of the atom was just empty space. Rutherford not only discovered the nucleus but also the protons with similar experiments with alpha particles.

1911

declanarcand — 2024-02-05 18:30:48 UTC

Niels Bohr went to England to study with Rutherford. Bohr's analysed the result of Rutherford gold foil experiment and was able to determine most of the time where the electrons in the atom are. This model is called the Planetary model.

1927

declanarcand — 2024-02-05 18:37:32 UTC

Theoretical physicist Werner Heisenberg gave us. one of the most important contributions to the modern atom. He mathematically found that is was impossible to to know both the momentum and exact position of an electron. telling us that we don't know that electrons are in a neatly circular orbit. is also help prove the theory that electrons are not particle nor waves but have characteristics of both. the area in which the electrons are found are called "orbits"