A German scientist invented the triads which was the first stepping stone to creating any kind of groups for the elements.
The triads was the first grouping of elements ever to be seen. Obviously by the name you can guess what how they were grouped. In threes.
The groups of threes were based on similar elements bin threes. The appearance and attributes that were similar to each other including different reactions to put them into their groups.
He also invented a amp called a tinder box which he was also widely known for.
Julius Lothar Meyer was a German Chemist and Mendeleev was Russian.
This seemed to be another table grouping ordered by the atomic mass of the elements.
Demitri used Meyers research to form his first draft of the periodic table.
He was an English scientist who made the law of Octaves.
He arranged the groups in order of their relative atomic mass. When doing this he found that the elements further eight more onwards in the sequence were the similar elements.
This were why they were called Octaves.
Lord Rayleigh found a gas heavier that didn’t react with anything. He named it Argon, which means “lazy” in Greek and was an amazing discovery.
William Ramsey was from Glasgow and he discovered neon, krypton, and xenon with Lord Rayleigh. Him and Lord Rayleigh learnt a lot about the elements together which was a big stepping stone for what we know as the periodic table.
He used X-ray to order the elements. Each element has a unique emission pattern when X-rayed. Moseley used this to show that atomic number, not atomic weight was most important in grouping the elements. Atomic number was a brand new thing and it is amazing how successful the idea was.
He was an American Chemist that worked on finding new elements (10 to be exact) and helped the discovery of Plutonium. This would lead to the invention of the atomic bomb.