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This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. Hypothetical chemical element, symbol Uue and atomic number 119 Chemical element with atomic number 119 (Uue) Ununennium, 119 Uue Theoretical element Ununennium Pronunciation / ˌ uː n. uː n ˈ ɛ n i ə m / ⓘ (OON -oon- EN -ee-əm) Alternative names element 119, eka-francium ...
Ancient history – Aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly five thousand years, beginning with the earliest linguistic records in the third millennium BC in Mesopotamia and Egypt .
The synthesis of ununennium was first attempted in 1985 by bombarding a sub-microgram target of einsteinium-254 with calcium-48 ions at the superHILAC accelerator at Berkeley, California: 254 99 Es + 48 20 Ca → 302 119 Uue * → no atoms. No atoms were identified, leading to a limiting cross section of 300 nb. [29]
Perey discovered it as a decay product of 227 Ac. [184] Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well. [185]
Its discovery is generally believed to have originated in India around the 4th century AD, [65] although Singaporean mathematician Lam Lay Yong claims that the method is found in the Chinese text The Nine Chapters on the Mathematical Art, from the 1st century AD. [66] 60 AD: Heron's formula is discovered by Hero of Alexandria. [67]
This is an accepted version of this page This is the latest accepted revision, reviewed on 22 February 2025. Periodic table of the elements with eight or more periods Extended periodic table Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium ...
Bone fragments unearthed in a cave in central Germany show that our species ventured into Europe's cold higher latitudes more than 45,000 years ago - much earlier than previously known - in a ...
The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (800 BC to AD 500), the Middle Ages (AD 500–1500), and the modern era (since AD 1500). The first early European modern humans appear in the fossil record about 48,000 years ago, during the Paleolithic era.