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List of chemical elements. 118 chemical elements have been identified and named officially by IUPAC. A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z ). [1]
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Juneteenth National Independence Day. Independence Day. Labor Day. Columbus Day. Veterans Day. Thanksgiving Day. Christmas Day. Federal holidays in the United States are 11 calendar dates designated by the U.S. federal government as holidays. On these days non-essential U.S. federal government offices are closed and federal employees are paid ...
Thanksgiving is a national holiday celebrated on various dates in October and November in the United States, Canada, Saint Lucia, Liberia, and unofficially in countries like Brazil, Germany and the Philippines. It is also observed in the Dutch town of Leiden and the Australian territory of Norfolk Island. It began as a day of giving thanks for ...
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups").It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of ...
The September 11 attacks of 2001, in addition to being a unique act of terrorism, constituted a media event on a scale not seen since the advent of civilian global satellite links. Instant worldwide reaction and debate were made possible by round-the-clock television news organizations and by the internet. As a result, most of the events ...
Wikipedia is a free online encyclopedia that anyone can edit, and millions already have . Wikipedia's purpose is to benefit readers by presenting information on all branches of knowledge. Hosted by the Wikimedia Foundation, it consists of freely editable content, whose articles also have numerous links to guide readers towards more information.
