Editing Physical quantity (section)

{{Short description|Measurable  property of a material or system}}
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[[File:Ampèremetre.jpg|thumb|Ampèremetre (Ammeter)]]

A '''physical quantity''' (or simply '''quantity''')<ref name="ISO 80000-1"/>{{efn|"The concept 'quantity' may be generically divided into, e.g. 'physical quantity', 'chemical quantity', and 'biological quantity', or 'base quantity' and 'derived quantity'."<ref name="ISO 80000-1"/>}} is a property of a material or system that can be [[Quantification (science)|quantified]] by [[measurement]]. A physical quantity can be expressed as a ''value'', which is the algebraic multiplication of a ''[[numerical value]]'' and a ''[[unit of measurement]]''. For example, the physical quantity [[mass]], symbol ''m'', can be quantified as ''m''{{=}}''n''{{nbsp}}kg, where ''n'' is the numerical value and kg is the unit symbol (for [[kilogram]]). Quantities that are vectors have, besides numerical value and unit, direction or orientation in space.