Name: J.J Thomson
DOB: 18 December 1856
In 1897, Thomson provided the first hint that an atom is made of even smaller particles.
He proposed a model of the atom that is sometimes called the “Plum Pudding” model.
"Atoms were made from a positively charged substance with negatively charged electrons scattered about, like raisins in a pudding."
During the time he studied the passage of an electric current through a gas, as the current passed through the gas, it gave off rays of negatively charged particles.
He thought in surprise, "Where did they come from?" because the atoms of the gas were uncharged! So where did the negative charges come from?
Thomson soon concluded that the negative charges came from within the atom. A particle smaller than an atom had to exist. The atom was divisible!
Thomson called the negatively charged “corpuscles,” today known as electrons.
Since the gas was known to be neutral, having no charge, he reasoned that there must be positively charged particles in the atom.
But he could never find them.