I'm not so sure but I would say it could be an iconic bond!
they send the radiation through the cords
Explanation:
Molecular formulas show correct and accurate number of each type of the atoms which are present in molecule.
On the other hand, structural formulas show arrangement of atoms and covalent bonds between them.
For example,
The molecular formula for carbon dioxide is
The structural formula is O = C = O
It would be barium sulfate