The phrase "an unknown element" is correct and usable in written English.
You can use it when referring to something that is not identified or recognized within a particular context, such as in scientific discussions or metaphorical expressions.
Example: "In the experiment, we discovered an unknown element that altered the results significantly."
Alternatives: "a mysterious factor" or "an unidentified component".
"There's still an unknown element," General Manager Jim Duquette said.
Propelling yourself into an unknown element – be it into the air from a zip-line or into water to swim with wildlife – always causes a strange feeling in the stomach, like a sobering warning.
There has to be an unknown element to be interesting".
Hertfordshire Mavericks assistant coach Kat Ratnapala has said there will be an unknown element to the Superleague in Commonwealth Games year.
Mean detection rates were less than 1 for all three genera (0.85, 0.66, and 0.63 for Dicamptodon, Rhyacotriton, and Ascaphus, respectively), which indicates that conclusions from previous research about relationships between SAA occupancy, environmental variables, and forest practices have an unknown element of uncertainty, particularly if detection rates co-vary with habitat change.
Eventually he realized that the sample was gold bonded with an unknown element.
The architect analysis detected two deficiencies: (i) code elements that did not have corresponding architectural components, e.g., FunctionalTypeTest class was considered to be part of an unknown component; and (ii) code elements that do not fit to the naming standards, e.g., classMailService had the characteristics of a persistence class and hence it was renamed to NotificationDAO.
It is possible that C. aeruginascens requires a nutrient not found in malt agar media; however continued stimulation with increasing wood amounts suggests an additional unknown element at play.
Sir Joseph Norman Lockyer, (born May 17, 1836, Rugby, Warwickshire, Eng. died Aug. 16, 1920, Salcombe Regis, Devon) British astronomer who in 1868 discovered in the Sun's atmosphere a previously unknown element that he named helium after Hēlios, the Greek name for the Sun and the Sun god.
May 17, 1836 Rugby, England August 16, 1920 Salcombe, England Sir Joseph Norman Lockyer, (born May 17, 1836, Rugby, Warwickshire, Eng. died Aug. 16, 1920, Salcombe Regis, Devon) British astronomer who in 1868 discovered in the Sun's atmosphere a previously unknown element that he named helium after Hēlios, the Greek name for the Sun and the Sun god.
Shortly after, the local animals, as well as Nathan's wife, begin to go mad and a previously unknown element is discovered in the property's well.
