3

The quantum-mechanical (relativistic) explanations for the observed colours of copper, silver & gold don't appear to explain the black colours of powdered silver (& powdered platinum). Can anyone help?

Qmechanic
  • 201,751
tony
  • 207
  • Related: https://physics.stackexchange.com/q/72368/2451 and links therein. – Qmechanic Jul 29 '18 at 12:46
  • 2
    Presumably at least powdered silver tarnishes really quickly when powdered and tarnished silver is black. –  Jul 29 '18 at 12:47
  • maybe a first step would be to give details of this “relativistic” theory and why you think it would apply to powdered substances? – ZeroTheHero Jul 29 '18 at 13:18
  • @ZeroTheHero: Apologies; a succint explanation of the quantum-mechanical explanation is given in the ref. above from Qmechanic. Further studies indicate, as tfb has said, that black, powdered silver is in fact silver I oxide. But black, powdered platinum is pure platinum. Is it anything to do with crystal-structure grain-boundaries warping the normal reflection observed from a bar of platinum? – tony Jul 30 '18 at 10:50

1 Answers1

0

Silver, is located in period 5, group 11 of the periodic table, and has an atomic number equal to 47. The last electron is added on in 4d.Now, you have to be a little careful with silver because it is a transition metal, which implies that the occupied d-orbitals are actually lower in energy than the s-orbitals that belong to the highest energy level. It is in degenerate sub-shell. The reactivity of silver is too high and the atom's has very less life time and it turn's black when it is solid state. When there is in change of state of matter from solid to liquid or gas the parameter like size,shape,etc. The change is so quick that we can't notice it.

Isthismohit
  • 1