The scientist we are looking for this time contributed to the development of the periodic table and the concept of valence. He or she published a periodic table with 57 elements but is not well known for this work.
Our chemist also proposed that carbon is tetravalent in 1855—independently from August Kekulé, who published and formalized this idea in 1858.
Who are we looking for? Send us an email with your answer to find out right away.