/sci/ - Science & Math

>>11506370
The total transmissivity of a surface, defined as the ratio of irradiant flux to total irradiation, is the integral of spectral transmissivity over all wavelengths and is basically a measure of how transparent a surface is to irradiation. This spectral transmissivity is a function of wavelength, obviously, and depends on electronic valences blah blah atomic scale blah blah. So basically you can have a very low over all transmissivity, or a spectral transmissivity of zero at one wavelength, but then be transparent at another. For example, iron is transparent at 1 meter, but invisible to 500 nanometer light. This is a good question and deserves a better response. Look into optics.
>>11511667
Look at the periodic table and think about how much water weighs. Since the atomic mass of H2O is about 2*1+16=18, and since there is specified to be 9 grams of it, we know we have half a mole of water. But since there are two hydrogens in a water, we know we have 1 mole of H. In other words, 9 grams of water contains 1 mole or 6.022E23 hydrogen atoms.
>>11519630
"The Scope proved to be a haunt for electronics assembly people from Yoyodyne. The green neon sign outside ingeniously depicted the face of an oscilloscope tube, over which flowed an ever-changing dance of Lissajous figures. Today seemed to be payday, and everyone inside to be drunk already. Glared at all the way, Oedipa and Metzger found a table in back. A wizened bartender wearing shades materialized and Metzger ordered bourbon. Oedipa, checking the bar, grew nervous. There wast his je ne sais quoi about the Scope crowd: they all wore glasses and stared at you, silent. Except for a couple-three nearer the door, who were engaged in a nose-picking contest, seeing how far they could flick it across the room."
>>11515474
In the copypasta that starts each thread.