Dmitri Mendeleev (1834 – 1907) Дмитрий Менделеев, “Principles of Chemistry”, 1868 was the topic of an earlier blog post.
Here I present: Frederick Soddy, (1877-1956) “The Origins of the Concept of Isotopes”, NOBEL PRIZE LECTURE, 12 November 1922.
The Scottish doctor/writer Margaret Todd (1859-1918) coined the term “isotope” in a suggestion to Frederick Soddy (1877-1956) the Scottish English radiochemist in 1913.
Frederick Soddy, “The Radioelements and the Periodic Law”, Chemical News, volume 107, year 1913, pages 97-99. was the source for the suggestion of the term “isotope” from Margaret Todd in 1913.
Isotope is a noun in the 1913 sense of the Margaret Todd definition. The term is composed of the Greek language “isos” (equal). The term is also composed of the Greek language “topos” (place). Hence, in the English language the term isotope, is to mean literally “having the same place”. Isotope is a variety of forms of the element occupying the same periodic table place.