Reason why tantalium became obsolete

A search in google clearly shows that the word tantalum is the correct spelling of the word and is widely used today. What made me curious was this Wikipedia entry wrote:

Previously known as tantalium...

So, I searched when this word come into usage. A search to google Ngrams shows this:

This clearly shows that a spike in the usage of the word tantalium in around 1802 which is about when 'tantalum' was discovered. Then slowly into the future closer to modern times, tantalium is now classified as obsolete.

I have a few questions relating to this:

1) Why is tantalium obsolete and made tantalum surpass it?

2) There is a spike in usage of the word tantalium just after the discovery of this metal. Could the word originally be named tantalium?

3) There was a small amount of usage of the word tantalum in 1747 and 1754, well before the discovery of such metal. What could be the cause of this?

Solution 1:

According to the OED Tantalium is only an early variant of the original name Tantalum. Tantalium first instance is from 1805, after tantalum was discovered and its name coined:

• An early variant of the name tantalum (after other names of metals in -ium).

Early usage examples:

• 1805 Nisbet Dict. Chem., Tantalium is a new metal, which has lately been discovered by Mr. Ekeberg, a Swedish chemist.
• 1839 Ure Dict. Arts 309 It is also called Tantalium.

Tantalum:

• One of the rare metals, occurring in combination in various rare minerals, and in certain metallic ores; discovered in 1802 by Ekeberg in two minerals, one from Finland and the other from Sweden, which he named tantalite and yttrotantalite. It has been isolated as a solid greyish-white colour and metallic lustre, and has been used for the incandescent filament in electric lamps. Atomic weight 182; symbol Ta. Also attrib., as tantalum lamp, etc.

• 1802 Ekeberg in Kongl. Vetenskaps Acad. Handl. XXIII. 80 (tr.) This new recruit among the metals I call Tantalum, partly following the custom which favours names from Mythology, partly in allusion to its incapacity, when immersed in acid, to absorb any and be saturated.