Things are shiny (reflective) if they are made up of a regular crystal structure. All elements can form crystal structures, but metals tend to be made up of elements, while non-metals tend not to. An example of shining non-metal is graphite (Carbon): if it's flat, and not roughened up because of a pencil sharpener, then it's a reflective surface. If we use metals, they also tend to be pure: it's just one giant lob of crystal. Non-metals are more often compounds or mixtures, giving texture to things. The metal is not transparent because the density of atoms is so great that light is reflected, rather than passed through. Because of the fact that it's a crystal, the reflection is always at the same angle as the angle it came in, regardless of where it hits the metal. Therefore, a reflection on a metal looks normal.
Things are shiny (reflective) if they are made up of a regular crystal structure. All elements can form crystal structures, but metals tend to be made up of elements, while non-metals tend not to. An example of shining non-metal is graphite (Carbon): if it's flat, and not roughened up because of a pencil sharpener, then it's a reflective surface. If we use metals, they also tend to be pure: it's just one giant lob of crystal. Non-metals are more often compounds or mixtures, giving texture to things. The metal is not transparent because the density of atoms is so great that light is reflected, rather than passed through. Because of the fact that it's a crystal, the reflection is always at the same angle as the angle it came in, regardless of where it hits the metal. Therefore, a reflection on a metal looks normal.
One characteristic of a metal is that the raw base metal has a highly reflective surface, i.e., metals are mostly shiny. However, that surface soon oxidizes to develop a skin. Sometimes the skin is soft, like red rust on iron. Or can be tight like chromium dioxide on stainless steel. Metals that are shiny in the environment like gold, develop the tightest oxide layer. The tighter the oxide layer, the longer the metal will stay shiny after the raw base metal is exposed to view. The looser the oxide layer, the more the oxide turns color and becomes opaque to light. Copper, for example, turns green, but the oxide layer is medium tight, so oxidation slows the thicker it gets until it almost stops unlike red rust which keeps going until forever or the base metal is all oxidized. Since copper oxidation slows so much even after a relatively short term exposure to air and moisture, copper sheeting on a roof will last much longer than shingles. Many cathedrals in Europe have copper clad roofing and the copper is still going strong. Slice into any elemental metal and the cut edge shines, at least for a little while.
Optically speaking, metals are opaque, shiny and lustrous. This is due to the fact that visible lightwaves are not readily transmitted through the bulk of their microstructure. The large number of free electrons in any typical metallic solid (element or alloy) is responsible for the fact that they can never be categorized as transparent materials
Optically speaking, metals are opaque, shiny and lustrous. This is due to the fact that visible lightwaves are not readily transmitted through the bulk of their microstructure. The large number of free electrons in any typical metallic solid (element or alloy) is responsible for the fact that they can never be categorized as transparent materials
One characteristic of a metal is that the raw base metal has a highly reflective surface, i.e., metals are mostly shiny. However, that surface soon oxidizes to develop a skin. Sometimes the skin is soft, like red rust on iron. Or can be tight like chromium dioxide on stainless steel. Metals that are shiny in the environment like gold, develop the tightest oxide layer. The tighter the oxide layer, the longer the metal will stay shiny after the raw base metal is exposed to view. The looser the oxide layer, the more the oxide turns color and becomes opaque to light. Copper, for example, turns green, but the oxide layer is medium tight, so oxidation slows the thicker it gets until it almost stops unlike red rust which keeps going until forever or the base metal is all oxidized. Since copper oxidation slows so much even after a relatively short term exposure to air and moisture, copper sheeting on a roof will last much longer than shingles. Many cathedrals in Europe have copper clad roofing and the copper is still going strong. Slice into any elemental metal and the cut edge shines, at least for a little while.
