Eka is a prefix for a chemical element which is listed in the periodic table under another element. Prefix has meanings in linguistics, mathematics and computer science, and telecommunications. ... A chemical element, often called simply element, is the class of atoms which contain the same number of protons. ... The periodic table of the chemical elements, also called the Mendeleev periodic table, is a tabular display of the known chemical elements. ...

The prefix eka- was used especially to name as yet undiscovered elements. For example germanium was called ekasilicon until its discovery. The prefix originates from the Sanskrit word "eka" meaning "one" and was coined by Dmitri Mendeleev. The prefixes dvi- and tri- from the Sanskrit prefixes meaning "two" and "three" respectively, have been used for undiscovered elements two or three places in the periodic table below the element providing the base name. Current offical IUPAC practice is to use a systematic element name based on the atomic number of the element as the provisional name, instead of being based on its position in the periodic table as these prefixes require. General Name, Symbol, Number germanium, Ge, 32 Chemical series metalloids Group, Period, Block 14, 4, p Appearance grayish white Atomic mass 72. ... General Name, Symbol, Number germanium, Ge, 32 Series metalloids Group, Period, Block 14 (IVA), 4 , p Density, Hardness 5323 kg/m3, 6 Appearance greyish white Atomic properties Atomic weight 72. ... The Sanskrit language ( संस्कृता वाक्) is one of the earliest attested members of the Indo-European language family and is not only a classical language, but also an official language of India. ... Portrait of Dmitri Mendeleyev by Ilya Repin Dmitri Ivanovich Mendeleyev (Russian: Дми́трий Ива́нович Менделе́ев   listen?) (8 February 1834 – 2 February 1907), was a Russian chemist. ... Prefix has meanings in linguistics, mathematics and computer science, and telecommunications. ... The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. ... In chemistry, heavy transuranic elements receive a permanent name and symbol only after their discovery has been confirmed. ... The atomic number (Z) is a term used in chemistry and physics to represent the number of protons found in the nucleus of an atom. ...

It has been speculated that the similarity between the tabular structure commonly used to present the Sanskrit abugida and the periodic table is what led to Mendeleev choosing to use Sanskrit as the basis of these prefixes. An abugida or alphasyllabary is a writing system composed of signs (graphemes) denoting consonants with an inherent following vowel, which are consistently modified to indicate other vowels (or, in some cases, the lack of a vowel). ...