Albert Einstein did not discover the atom. The concept of the atom existed long before Einstein's time, dating back to ancient Greek philosophers like Democritus.

Here's a breakdown:

* Ancient Greece (5th century BC): Democritus proposed the idea of atoms as the fundamental, indivisible particles that make up everything.

* 1803: John Dalton revived the atomic theory, proposing that elements are made up of specific types of atoms.

* 1897: J.J. Thomson discovered the electron, providing evidence for the existence of subatomic particles.

* 1911: Ernest Rutherford proposed the nuclear model of the atom, which placed a dense, positively charged nucleus at the center with electrons orbiting around it.

Einstein's contributions to physics were revolutionary, but they focused on relativity, the photoelectric effect, and Brownian motion. He did not directly contribute to the discovery of the atom.