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The element with atomic number 137, dubbed untriseptium or eka-dubnium is a hypothetical element never known to have occurred in nature or synthesized in a laboratory. The element's existence is in question due to its drip instabilities. A simplistic interpretation of the relativistic Dirac equation suggests that the element cannot exist as a neutral atom when the atomic number reaches 137. This was first noted by a physicist. Hence this hypothetical element was named after him.

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