Identifying the Predicted Element Below Aluminium

Dmitri Mendeleev, a pioneering Russian chemist, is famous for his work on the periodic table. While developing his table, he noticed gaps where elements were yet to be discovered. He didn't just leave these gaps; he predicted the properties of these missing elements based on their position in the table.

Mendeleev's Naming Convention: The 'Eka' Prefix

To name these predicted elements, Mendeleev used a systematic approach based on Sanskrit words. He prefixed the name of the element directly above the predicted element in the same group with "Eka". "Eka" is a Sanskrit word meaning "one".

• For the element predicted below Boron, he used the name Eka-Boron.
• For the element predicted below Aluminium, he used the name Eka-Aluminium.
• For the element predicted below Silicon, he used the name Eka-Silicon.

Therefore, the unknown element predicted to be under aluminium in Mendeleev's periodic table was called Eka-Aluminium.

Discovery of Eka-Aluminium's Counterpart

Mendeleev's prediction was remarkably accurate. The element Eka-Aluminium was later discovered in 1875 by French chemist Paul-Émile Lecoq de Boisbaudran. This newly discovered element was named Gallium (Ga). Its properties closely matched Mendeleev's predictions for Eka-Aluminium, confirming the power of his periodic table.

The question asks for the name given to the unknown element under aluminium. Based on Mendeleev's naming convention, this element was known as Eka-Aluminium.

Among the given options, Eka-Aluminium correctly identifies this predicted element.