This element was known and used by ancient people?

Answer 1

There were several elements that would have been encountered in their simple substance form and used by ancient people. They would not have been recognised as 'elements', but they were certainly exploited in the various ancient cultures

Copper and gold in their native form as simple substances have been used to make ornaments for at least 7000 years, and silver perhaps only a little less. Sulfur is encountered in its simple substance form as a yellow encrustation around volcanic fumraoles and in similar settings. Carbon as coal outcrops to the surface in many places, or, as charcoal, it would have been produced in early campfires and used for fuel, drawings, and as body paint.

When the smelting process, initially to produce copper from its ores, was discovered, a new phase of civilization began. We refer to it as the "Bronze Age". This innovation led fairly rapidly to the discovery and use of lead, tin, and Mercury. Much later, just a few centuries BC, the secret of making iron metal (basically very hot forced-air furnaces) was discovered, and we entered the "iron age".

So there were basically just 9 of the simple substances we now recognize as elements known to early civilisations:

The 7 metals copper, gold, silver, mercury, tin, lead, and iron, and

the 2 non-metals carbon and sulfur.

Answer 2

Periodic Table or radioactive elements i think

Answer 3

The element is Argon