You can not see between opaque materials because light cannot pass through them.
They represent elements by using symbols
The energy that is
essential to break one C-H bond is 414 kJ/mol. Since, there are four C-H bonds
in CH4, the energy Δ HCH4 for
breaking all the bonds is calculated as Δ HCH4 = 4 x bond energy of C-H bond. By
multiplying the 4 with the 414 kJ/mol you can get the answer of 1656 kJ/mol CH4
molecules.
we have,
wavelenght=c/f
where c= 3×10^8 m/s
f=6.3×10^12 s^-1
so wavelength=(3×10^8)/(6.3×10^12)
=0.476×10^-4 m