What was the unknown element under aluminium called?

Correct option is C

The correct answer is (C) Eka-Aluminium

Explanation:

• The unknown element that was predicted to exist below aluminium in the periodic table was referred to as Eka-Aluminium.
• The term Eka-Aluminium was coined by the famous chemist Dmitri Mendeleev in 1869 when he formulated the Periodic Table of Elements.
• Mendeleev predicted that there was an element with properties similar to aluminium but with a higher atomic mass, and he placed it in the periodic table in the position below aluminium, which was not yet discovered at the time.
• This element was later identified as Gallium in 1875 by Paul-Émile Lecoq de Boisbaudran, confirming Mendeleev's prediction.

Information Booster:

• Eka-Aluminium means "one beyond aluminium" (Eka means "one" in Sanskrit), reflecting Mendeleev's prediction of an element in the same group as aluminium, but with a higher atomic number.
• Gallium (Ga) was discovered after the prediction and is chemically similar to aluminium, matching the properties Mendeleev had foreseen for Eka-Aluminium.

Additional Knowledge:

• Neo-Aluminium: This term is not associated with any known element in the periodic table.
• Proto-Aluminium: This term is also not used in the context of element predictions.
• Meta-Aluminium: Like the other terms, it is not a recognized term in the history of the periodic table.