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Silver Color and Transparent Glass
Name: Michiru K.
Status: student
Age: 18
Location: N/A
Country: N/A
Date: 2000-2001
Question:
Leaves appear green in colour because they reflect
green colour while absorbing others. Black absorbs all the wavelengths
in the visible spectrum while white reflects all of it. My questions
are:
1) What wavelengths does silver colour reflects/absorbs?
2) Why is glass transparent?
Replies:
Answer to question 2 - why is glass transparent ?
The reason why metal reflects light lies upon the fact that the bonding
between atoms of metal are made up of free electrons. Free electrons
cause the light to be reflected and the surface of a metal like silver
happens to be
brilliant. On the other hand, the atomic bonds between Silicon, Oxygen,
Calcium,
Sodium, Lead, Bhorium, etc, are predominantly covalent which in return
allows the light to travel through it. Without the presence of free
electrons
the light finds ist way through the glass crystal. And - furthermore - can
sometimes find it in two or three directions ( like for instance in calcite
:
CaCO3 with two directions ). Because of the interference between the
electromagnetic nature of the light and that of the transparent crystal,
the light travels through it with slower speed (in one, two or more
directions).
Answer to question 1 - what wavelength does silver colour reflect/absorb ?
Based upon the arguments used on the answer nr. 1, the silver colour
reflects almost all the wavelenghts that strike on its surface, whatever its
origin !!!. Including radiant energy of fire ( observe the silver coating
cloth
of men that fight against fire ). Likewise the brilliant internal surface of
the
thermalflask avoid scaping of radiant energy.
Alcir Grohmann
Mirrors (silvered surfaces) reflect almost all incident light by specular
reflection, i.e. no scattering so that the angle of incidence equals the
angle of reflection. This distinguishes it from a white surface that
reflects almost all incident light but at various angles of reflection.
Glass is transparent because it reflects very little of the incident light.
It bends the incident ray of light, but reflects very little of it.
Vince Calder
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Update: June 2012
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