Timeline by Ivan Kretov

2500 BCE -Origin of Atomic Theory

vokreta — 2024-11-13 19:42:40 UTC

Approximately 2500 years ago ancient Greek philosophers - Leuccipus and Democritus came up with an idea that you can divide something in half so many times you will get something indivisible - A TOMOS, or an atom, as we call it now. They thought, that the cheese is made of yummy cheese particles, clay is made of flexible clay particles and iron is made of particles, tough like weights on hooks.

1897 - Discharge Tubes (Electron discovery)

vokreta — 2024-11-13 19:53:40 UTC

Electron was discovered by JJ Thompson by measuring heat of rays and how they were able to be bent by magnets; Their mass were calculated to be 1000 times less then the mass of the Hydrogen atom, believed to be the smallest particle.

1904 - Plum Pudding

vokreta — 2024-11-13 19:58:41 UTC

A model proposed my JJ Thompson; First model of electrons distribution - random at positive charged matrix. No concentrated positive charge.

1911 - Discovery of the Nucleus

vokreta — 2024-11-13 20:02:46 UTC

Earnest Ritherford experiment with a golden soil. In it, some amount of alpha particles was deflected, proposing a concentrated, though small, positive charge - nucleus.

1913 - Bohr's model

vokreta — 2024-11-13 20:05:12 UTC

As Rutherford proposed there were electrons. Bohr proposed that electrons were neatly placed on set orbits around a dense nucleus.

1926-27 - Quantum Theory, Electron Probability Cloud model

vokreta — 2024-11-13 20:14:19 UTC

Erwin Schrödinger, in 1926, proposed the described the behaviour of atoms as wave functions. Born, interpreted wave functions and proposed that electrons positions are not fixed but represented as probability clouds. In 1927, Heisenberg proposed that it is impossible to know both the momentum and the coordinate of an electron around the nucleus in the exact moment at time, meaning that electrons possess both properties of particles and waves and neither (Wave-particle duality). This is the basis for modern understanding of the atom's structure via electron clouds and tine dense nucleus.