Attractive antennas that pull the waves tword it.
No, the elements are not always transparent.
<u>Explanation:</u>
The elements become transparent when the light passes through those elements. Transparency is caused because of the transmission and the passing of the light waves through these elements.
But the metals do not become transparent even when the light waves pass through these metals. Metals do not become transparent because the refractive index in them is very big.
B I think is right. Hope this helps!
Every single bond is a sigma bond.
A double bond contains 1 sigma bond and 1 pi bond.
A triple bond contains 1 sigma bond and 2 pi bonds.
For example, in acetylene, H-C≡C-H, the sigma bond is formed by the head-on overlap of two sp orbitals. The pi bonds are formed by the side-on overlap of 2p orbitals.