Not all elements in existence are found on the Periodic Table. Including those seen and taken for granted every day.
The elements found on the Periodic Table are limited to being only those which can be weighed and measured and which can offer mass of some kind. Tangible. Definable.
When the great event happened - that split second which brought about all you know and have yet to discover - some things moved faster than others through the void. Those things with physical mass moved the furthest the fastest and brought about great chaos through collisions, rebounds, explosions and sudden stops. But imagine a bullet from a gun for a moment. The bullet speeds away leaving a trail of smoke, heat and fumes behind it. In the void of space those elements which trailed after the bullet never stop moving forward. There's no gravity to stop them from following the bullet albeit much slower.
On your world you have not yet added the slowest of these elements to be pushed outward. You believe that since you cannot measure them, weigh them, define them, that they are not elements at all.
I travelled aimlessly for billions of your years through the void. I could not be measured or weighed. I could not effect anything which came by me close enough to touch. Not until a very small cluster of an unremarkable and unstable metal hurdled just within the edge of my being.
Suddenly I was attached to the cluster. I found myself balling up in the center of its shapeless mass out of pure instinct or perhaps simply the instinctual desire to no longer be formless and ineffectual. I could bond with this material. Over several eons I learned to move it, change it, control its shape and functionality.
Eventually I encountered more of this unremarkable ore and I added it to my own mass and grew in size and strength. My shape refined and I found myself being able to refine other shapes to fit my needs as I encountered primordial planets in young galaxies. I travelled from one to the next by instinct only. I had no language. I knew not what I was seeking.
Then, in a dark galaxy with a dim star I found entire planets and moons comprised of the same ore which was now my physical form. I touched down on the largest of the planets. With that first contact I felt a connection with the ore unlike anything I can explain. From my shapeless being within it seemed I had brought life itself to an inanimate and otherwise lifeless planet.
Your species cannot exist without this element. Your species and mine possess this element but have evolved in both very similar and very different ways. On Earth you've referred to it as the Soul, Chi, Sentience, Consciousness ...
My species has christened it as the minuscule fragment it is from the great explosion which brought forth all there is.
We call it our Spark.