I would say that 'matter' was shown to be based on basic particles long before the confirmation of the existence of the electron. Relatively ancient Chemistry had shown that elements combine in fixed ratios to form compounds. Lavoisier (late 18th century) was well on the way to the basic principles with his early stab at a Table of Elements. Of course, this was far from what was discovered later about the structure of atoms but their 'existence' as building blocks of chemistry was 'strongly indicated' more than two hundred years ago. (Makes one feel quite humble aamof.)mheruian said:just because the electron was discovered
The existence of atoms was first theorized by ancient Greek philosophers such as Democritus and Leucippus in the 5th century B.C. They believed that all matter was made up of tiny, indivisible particles called atoms.
The first experiment to provide evidence for the existence of atoms was conducted by English chemist John Dalton in the early 19th century. He observed that elements combined in whole number ratios, which supported the atomic theory proposed by the ancient Greeks.
In the early 20th century, scientists such as Ernest Rutherford and Niels Bohr conducted experiments using particles and radiation to study the structure of the atom. They discovered that atoms were made up of a positively charged nucleus surrounded by negatively charged electrons orbiting around it.
The development of advanced microscopes, such as the scanning tunneling microscope, allowed scientists to directly observe and manipulate individual atoms. This technology played a crucial role in confirming the existence of atoms and studying their properties.
Scientists continue to study atoms using advanced technologies and experiments. The Large Hadron Collider, for example, allows scientists to smash particles together at high speeds to study the fundamental building blocks of matter. This ongoing research helps to further our understanding of atoms and their role in the universe.