1 mole of a pure substance has a mass equal to its molecular mass expressed in grams.
This is known as the molar mass, M, and has the units g mol-1
So 2 moles of a substance would have a mass = 2 x molar mass
3 moles of a substance would have a mass = 3 x molar mass etc
This leads to the formula: mass = moles x molar mass
If we let:
m = mass of substance in grams,
n = moles of pure substance,
M = molar mass of the pure substance in g mol-1
we can write the equation: m = n x M
This equation can be rearranged to give the following:
n = m ÷ M (moles = mass ÷ molar mass)
M = m ÷ n (molar mass = mass ÷ moles)
Molar mass SiO2 = 28 + 32 = 60
<span>so moles sand = 3.4 x 10-7 / 60</span>
Well - it depends on where you start and where you finish on the electromagnetic spectrum. But by most estimates, we're can see about 0.0035% of the electromagnetic spectrum (that includes gamma rays, radio waves, x-rays, infrared, ultraviolet, microwaves, etc.).
<em>Hope this helps</em>!
The wavelength that represented photons is at <span>lambda = 376.4 nm.
The wavelength with the higher energy is at </span><span>lambda - 372.1 nm.
The longer wavelength is, of course, </span> at lambda 376.4 <span>nm.
The wavelength with the higher frequency is </span> 376.4 <span>nm.</span><span>
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