The side element is called a vent.
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Casement Park.
Casement windows are hinged on the side and can actually swing in or out. The name comes from the fact that they slide vertically in their cases.
The name uranium is derived from the name of the planet Uranus.
Some were were given symbols from their names in other languages.
it has not yet been discovered
The element, 'Oxygen' is abbreviated to 'O'.
Na is "short" for natrium, an original name given to the element sodium.
muntin or mullion
Element 113 has the temporary name of Ununtrium. It has not yet been given a permanent name.
They are called as isotopes of the given element.