He was one of the first scientists to discover an atom. He suggested that all matter was made up of small units called atoms.

He was considered to be one of the most influential men in atomic structure history. Dalton thought a solid sphere represented an atom.

One of the most important discoveries in history came from him. He discovered the periodic table of elements.

He had many achievements, one of them being that one of his first discoveries was Thallium.

He discover the electrons and he was said to be the first person to show that atoms are made up of even smaller particles.

He was the man who discovers protons and the nucleus. He suggested that electrons orbited the nucleus of an atom.

He came up with the Planetary model that claimed the charged centre is surrounded by revolving electrons on rings.

He came up with many different advances in atomic structure. He also discovered that the noble gases were stable due to there being eight electrons at the outermost shell.

He invented the Geiger counter that measures radiation and he introduced the first successful detector.

He determined the unit charge for electrons by using an oil drop experiment to charge a single electron.