Search results
Results from the WOW.Com Content Network
The Limestone Tombs of Kamhantik refer to the excavated remains of a thousand-year-old barangay (a term used to connote a polity during the classical era) found in the jungles of Mount Maclayao in Sitio Kamhantik within the Buenavista Protected Landscape of Mulanay, Quezon, Philippines. It is widely believed that pre-colonial Tagalog people ...
Actinium is a chemical element; it has symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium ...
The Tabon Caves is a cave system located in Lipuun Point, Panitian, Quezon, Palawan in the Philippines.Dubbed as the country's "cradle of civilization", [1] it is a site of archaeological importance due to the number of jar burials and prehistoric human remains found starting from the 1960s, most notably the Tabon Man. [2]
The Republic of the Philippines ratified the convention on September 19, 1985, making its historical and natural sites eligible for inclusion on the list. The country had its first sites (the Baroque Churches and Tubbataha Reefs Natural Park ) included in 1993, and now has six sites, the latest being the Mount Hamiguitan Range Wildlife ...
The Manunggul Jar is a secondary burial jar excavated from a Neolithic burial site in the Manunggul cave of the Tabon Caves at Lipuun Point in Palawan, Philippines.It dates from 890–710 B.C. [2] and the two prominent figures at the top handle of its cover represent the journey of the soul to the afterlife.
The actinide series is a group of chemical elements with atomic numbers ranging from 89 to 102, [note 1] including notable elements such as uranium and plutonium.The nuclides (or isotopes) thorium-232, uranium-235, and uranium-238 occur primordially, while trace quantities of actinium, protactinium, neptunium, and plutonium exist as a result of radioactive decay and (in the case of neptunium ...
Actinium-227 is the most stable isotope of actinium, with a half-life of 21.772 years. It mainly (98.62%) undergos beta decay, but sometimes (1.38%) it will undergo alpha decay instead. [1] 227 Ac is a member of the actinium series. It is found only in traces in uranium ores – one tonne of uranium in ore contains about 0.2 milligrams of 227 Ac.
Actinide chemistry. Plutonium is a transuranic radioactive chemical element, an actinide metal. Actinide chemistry (or actinoid chemistry) is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium.