The term "brightness" can have different interpretations depending on the context. If you're referring to the metal with the highest reflectivity or ability to reflect light, then silver is considered one of the brightest metals. It has a very high reflectivity, with around 95-98% of visible light being reflected off its surface. This property makes silver appear very bright and shiny.
However, if you're referring to the metal that emits the most light when heated or subjected to certain conditions, then it would be different. For example, when heated, certain metals like magnesium or aluminum can emit intense white light, which can be perceived as brightness. In terms of luminosity or light emission, these metals can appear brighter than silver.
So, the concept of brightness in metals can vary depending on whether you're considering reflectivity or light emission.