All elements have a useful purpose, including the synthetic actinides that have half-lives measured in milliseconds.
Ofc
For cosmologists, all elements except hydrogen and helium are considered to be "metals".For ordinary purposes, some metallic elements are:lithiumberyliumsodiummagnesiumaluminumpotasiumcalciumscanfdiumtitaniumvanadiumchromiummanganeseironcobaltnickelcopperzincgalliumrubidiumstrontiumyttriumzerconiumniobiummolybdenumtechnetiumrutheniumrhodiumpaladiumsilvercadmiumindiumtincesiumbariumlanthanumceriumpraseodymiumneodyniumpromethiumsamariumeuropiumgadoliniumterbiumdysprosiumholmiumerbiumthuliumytterbiumlutetiumhafniumtantaliumtungstenrheniumosmiumiridiumplatiniumgoldMercurythalliumleadbismuthpoloniumfranciumradiumactiniumthoriumprotactinumuraniumneptuniumplutoniumamericiumcuriumberkeliumcaliforiumeinsteiniumfermiummendeleviumnobeliumetc.
All are to someone, somewhere at some time.
None
Because it organized all of the existing elements and helped scientist discover more elements.
The typical useful life of a computer for depreciation purposes is around 3 to 5 years.
The useful life of a laptop for depreciation purposes is typically considered to be around 3 to 5 years.
No
This question is based on chemistry. Halogens are useful elements. There are 5 halogens in the world.
Almost all elements have some properties which are useful and so they can be used for that purpose.
All around us are natural or artificial compounds (excepting elements).
Prediction.